The linebackers' main role is run support; they line up anywhere between the defensive ends. They can be stacked on the tackles or offset either inside or outside, depending on the tackles' alignment. Pass coverage responsibilities are for running backs coming out of the backfield, running backs in the slot formation, or, in some situations, tight ends. The defensive backs' first concern is to watch for the pass; they are responsible for the ends. They may cover a running back in the slotback position, leaving the tight end for the linebacker. In run plays, they act as a second set of linebackers.