From now on it will take a lead role in co-ordinating and monitoring tougher financial regulations and serve (along with the IMF) as an early-warning system for emerging risks.

ECONOMIST: A new chapter for the world economy, maybe

Now, he says, the economic challenges the country faces are so great that Barack Obama should take a lead role in getting a new stimulus package through the lame duck Congress.

NPR: To Face Economic Crisis, Obama Moves Quickly

But the BBC's political editor Nick Robinson says the moment at which Afghan troops take a "lead combat role" is being gradually speeded up.

BBC: Cameron and Obama to agree Afghan combat role timetable

Goldman Sachs is expected to take the lead role in a Facebook IPO because of its relationship with the company now.

FORBES: LinkedIn: IPO To Get First Mover Advantage?

As chairman of the House Budget Committee, Ryan will take the lead role in crafting a blueprint expected to rely heavily on savings from benefit programs.

NPR: Debt Crisis Averted _ But Spring Fight Still Ahead

This spring, our forces will move into a support role, while Afghan security forces take the lead.

WHITEHOUSE: State of the Union 2013

Douglas Hodge will take the lead role in Osborne's play, about a middle-aged lawyer facing a midlife crisis.

BBC: Jude Law returns for Michael Grandage's Donmar farewell

Two of the school's 12 teachers take on administrative duties as "lead teachers, " performing the traditional role of a principal.

CNN: Teacher turns 'crazy idea' into new school

This week, we agreed that this spring, Afghan forces will take the lead for security across the entire country, and our troops will shift to a support role.

WHITEHOUSE: Weekly Address: Ending the War in Afghanistan and Rebuilding America | The White House

And today, we agreed that as Afghan forces take the lead and as President Karzai announces the final phase of the transition, coalition forces will move to a support role this spring.

WHITEHOUSE: President Obama and President Karzai Hold a Press Conference | The White House