Martin Sheen is in talks to play Uncle Ben the new Spider-Man movie from Marc Webb. 
Uncle Ben and his Aunt May were responsible for raising Peter Parker.  He is a pivotal character in this story because it is his death during a burglary that causes Parker to use his superpowers to fight crime.  

Sheen is a great addition to the cast which also includes Andrew Garfield as Parker, Emma Stone as love interest Gwen Stacy and Rhys Ifans as the movie’s unnamed villain.  Shooting is scheduled to begin in December.

Source: THR