Breakthroughs galore: A transformative year in medicine
This year has seen the dawn of gene editing, the rise of immunotherapy and the first hints of a drug to slow the pace of Alzheimer's disease.
They could all be breakthroughs that change medicine for all of us.
Meet Layla Richards, the baby who marked a new era of medicine.
On the day before her first birthday, Layla's parents were told that all treatments for her leukaemia had failed and she was going to die.
The determination of her family, doctors and a biotechnology company led to her being given an experimental therapy that had previously been tried only in mice.
The "miracle" treatment that has so far saved her life was a tiny vial filled with genetically engineered immune cells that were designed to kill her cancer.
It raises the prospect of similar methods being used to treat a whole range of genetic disease.
Meanwhile earlier this year, a group in China announced it was the first to successfully edit the genome of a human embryo.
The breakthrough at Sun Yat-sen University in Guangdong showed the errors in DNA that led to a blood disorder, beta thalassaemia, could be successfully corrected in embryos.
The techniques have thrown up a huge number of ethical issues including concerns about the creation of designer babies.
A pivotal meeting of the world's leading scientists said it would be "irresponsible" to allow the creation of genetically altered humans, but that basic research involving embryo gene editing should continue.
Cancer medicine is on the cusp of a revolution after one of its most promising fields - immunotherapy - finally came of age.
If you have flu, your immune system seeks out and destroys the virus. But tumours can masquerade as healthy, normal tissue to evade assault.
Immunotherapy stops cancer hiding and exposes it to the immune system.
Data from two large trials presented at the American Society of Clinical Oncology annual conference showed lung cancer survival was doubled in some patients with such an approach.
And tumours were shrunk in nearly six out of 10 patients with advanced melanoma cases.
But the averages hide some remarkable stories. The few patients who responded best to treatment went from terminal cancer to no cancer at all.
This is one of the hottest fields in medicine.
The relentless march of antibiotic resistance continued this year and took a significant scalp.
Some doctors declared that the world was now on the cusp of a "post-antibiotic era" after finding bacteria resistant to drugs used when all other treatments have failed.
They identified bacteria able to shrug off the drug of last resort - colistin - in patients and livestock in China.
Resistance has since been found in Europe, Africa and other parts of Asia.
It raises concerns of the "antibiotic apocalypse" in which treatments fail and chemotherapy, surgery and organ transplants become near impossible.
However, resistance is only a problem for as long as there are no new drugs coming through.
But in a sign that the apocalypse might yet be averted, a team in the US believe the decades-long drought in antibiotic discovery could be over.
The team at Northeastern University in Boston developed a novel method for growing bacteria that has yielded 25 new antibiotics, with one deemed "very promising".
Testing on the drugs is continuing to see if they are suitable for medical use.
Frozen baby first
A woman in Belgium was the first in the world to give birth to a baby using ovarian tissue frozen when she was still a child.
The 27-year-old had an ovary removed when she was 13 before invasive treatment for sickle cell anaemia that would affect her fertility.
Her remaining ovary failed following the treatment.
Ten years later, she decided she wanted to have a baby, so doctors grafted four of her thawed ovarian fragments onto her remaining ovary and 11 fragments onto other sites in her body.
She gave birth to a baby boy.
Men normally freeze their sperm before similar treatment, but the hope is similar techniques will work in pre-pubescent boys who have not yet started producing sperm.
Million dollar face
US surgeons carried out the world's most extensive face transplant to date in August, including the entire scalp, ears and eyelids.
It took 26-hours of surgery to give injured volunteer firefighter Patrick Hardison, aged 41, a new face.
Mr Hardison, who was injured in a house fire as he attempted to rescue a woman he believed was trapped in the blaze, had third degree burns of his entire face and scalp.
He waited more than a year on a donor register for a perfect match - not only blood type but someone with fair skin and light hair.
He will soon have more operations to remove some of the loose skin around his eyes and lips.
The donor was a 26-year-old, David Rodebaugh, who was fatally injured in a cycling accident.
Meanwhile a man in Texas had the world's first skull and scalp transplant.
The first details of how a drug could slow the pace of brain decline for patients with early stage Alzheimer's disease emerged this year.
Data from pharmaceutical company Eli Lilly suggested solanezumab can cut the rate of the dementia's progression by about a third.
The death of brain cells in Alzheimer's is currently unstoppable.
Solanezumab may be able to keep them alive by attacking the deformed proteins, called amyloid, that build up in the brain during Alzheimer's.
The findings were met with cautious optimism and all eyes are on the results of the full trial which are expected next year.
Brain barrier breached
For the first time, doctors breached the human brain's protective layer to deliver cancer-fighting drugs.
The barrier normally prevents infections and toxins from affecting the central nervous system.
The Canadian team used tiny gas-filled bubbles, injected into the bloodstream of a patient, to punch temporary holes in the barrier.
A beam of focused ultrasound waves applied to the skull made the bubbles vibrate and push their way through, along with chemotherapy drugs.
The technique could be useful in cancer, dementia and Parkinson's disease, but more safety studies are still needed.
In other news
A few other stories managed to catch the headlines in 2015:
- The world's first successful penis transplant has been reported by a surgical team in South Africa. And it works! The recipient's partner is now pregnant.
- Young children who have a pet dog in the home are less likely to go on to develop asthma, a large Swedish study has found.
- Scientists at the University of Oregon discovered that everyone is surrounded by a unique "cloud" of millions of their own bacteria.
- Elephants have enhanced defences against cancer that can prevent tumours forming.
- A man has died with tumours made of cancerous parasitic worm tissue growing in his organs.
- But some species of parasitic worm increases the fertility of women, say scientists.
- The way the body can track the passing of the seasons in a "chemical calendar" has been discovered by scientists.
- All men should bank their sperm at the age of 18 because of the risks of being an older father, according to one bioethicist.
- Ancient DNA records show that plague has been a scourge on humanity for far longer than previously thought.
- Scientists say they have developed a way of testing how well, or badly, your body is ageing.