The brother of James Foley, the US journalist killed by Islamic State militants last year, has said he feels a sense of solidarity with the families of those who died in the Paris attacks.
Shootings and bomb blasts left 129 people dead and hundreds wounded, with more than 100 in a critical condition.
The attacks have been described as an "act of war" organised by the Islamic State (IS) militant group.
Those who died "are in our prayers", Michael Foley told the BBC.
"All these lives matter," he said.
"Their deaths are not in vain. It's very important to continue to push their memory, so that the rest of us don't forget what they gave up, what they lost."
More on the Paris attacks
On Thursday, the US said it was "reasonably certain" that a US drone strike in Syria killed the Islamic State militant known as "Jihadi John".
Mohammed Emwazi, a Kuwaiti-born British militant, appeared in videos of the beheadings of Western hostages, including US journalist James Foley in August 2014.
Mr Foley's brother Michael said Emwazi was a "misguided lowlife".
"I pray for the others that are still over there."
Mr Foley said he thought about his brother every day and the tragedy of the Paris killings would have "torn him apart".
"He lived in the middle of daily attacks in Aleppo. He saw what it did to the families. It drew him closer to the conflict."
"This was an everyday occurrence in northern Syria. I know it would have torn him apart. It's important that Jim's lasting memory and message continue to ring through.
"We need to get behind our journalists, who allow the world to see what's going on in these regions.
"It's very important, as we can see from what can happen from these groups," he said.