Harlequins back-row forward Jack Clifford has signed a new contract with the Premiership club.
The 22-year-old has scored eight tries in 38 appearances for Quins since making his debut for the club in 2012.
"Jack is one of a new breed of players coming through the system," director of rugby Conor O'Shea said.
"For me he has the potential to become one of the very best players in world rugby and to be a great leader within the group."
Clifford captained England to the Under-20 Six Nations title and victory in the Junior World Cup in 2013.
"I have been associated with Harlequins for close to 10 years and I can't think of anywhere better to be as I continue to gain experience and develop my career," he said.
"There are a number of influential and experienced players within the squad and I am looking forward to continuing to learn within such a competitive and highly-skilled back row."
Harlequins have not disclosed the length of Clifford's new deal at the Twickenham Stoop.