The protein encoded is a member of the tumor necrosis factor (TNF) ligand family: a cytokine ligand for TNFRSF14 may function as a costimulatory factor for the activation of lymphoid cells and as a deterrent to infection by herpesvirus. This protein has been shown to stimulate the proliferation of T cells and trigger apoptosis of various tumor cells. The gene discussed is TNFRSF14; the disease is neoplasm.