Does the PI of a multidisciplinary proposal have to be from the lead department that will primarily benefit?

The PI of a multidisciplinary proposal does not have to be a member of the lead department, but the proposal should provide a rationale for the choice. Given the departmental focus of the program and the requirement that multidisciplinary projects be rooted in and primarily benefit a discipline eligible in the funding cycle, consultants will very likely have questions about the selection of leadership which should be addressed explicitly.