Dr. Erica Hahn (Brooke Smith) sizes up her sexy surgeon counterparts Derek Shepherd (Patrick Dempsey) and Mark Sloan (Eric Dane). Gotta love these three together!

Derek and Mark used to be best friends. Slowly they've been building that back up. Can it be back to the old days again?

They do their thing, as always! Mark, Izzie and Callie tend to a patient played by guest star Ben Vereen in an early Season Four episode of "Grey's Anatomy."

Mark Sloan (Eric Dane) shows us a rare smile in an early episode of Season Four of Grey's Anatomy. Hopefully this fellow will be smiling more in this exciting new campaign.

The Season Four cast of Grey's Anatomy: Starring the lovely Ellen Pompeo (Meredith Grey), Patrick Dempsey (Derek Shepherd), Sandra Oh (Cristina Yang), Katherine Heigl (Izzie Stevens), T.R. Knight (George O’Malley), Justin Chambers (Alex Karev), Chandra Wilson (Miranda Bailey), James Pickens, Jr. (Richard Webber), Sara Ramirez (Callie Torres), Eric Dane (Mark Sloan) and Chyler Leigh (Lexie Grey).

Mark Sloan won't be Chief, but he made the rest of the candidates vying for it work harder.

Please, Mark asks?

Mark in his usual rouge glory.

(after Meredith shoots down his offer of revenge sex)

Cristina, Mark and Meredith look on.

Mark makes a pass at Meredith... to no avail.

But Addison has eyes on someone else... and a different life entirely.