The protein encoded by this gene is a cytokine that belongs to the tumor necrosis factor (TNF) ligand family. This protein is a ligand for the FN14/TWEAKR receptor. This cytokine has overlapping signaling functions with TNF, but displays a much wider tissue distribution. This cytokine, which exists in both membrane-bound and secreted forms, can induce apoptosis via multiple pathways of cell death in a cell type-specific manner. This cytokine is also found to promote proliferation and migration of endothelial cells, and thus acts as a regulator of angiogenesis. Alternative splicing results in multiple transcript variants. Some transcripts skip the last exon of this gene and continue into the second exon of the neighboring TNFSF13 gene, such read-through transcripts are contained in GeneID 407977, TNFSF12-TNFSF13.