APRIL, an acronym for a proliferation inducing ligand is a TNF superfamily molecule. APRIL is expressed in myeloid cells, monocytes, and macrophages and appears to be involved in tumor cell regulation. It is highly expressed in certain transformed cell lines, certain colon carcinomas, and lymphoid tissues. APRIL enhances tumor cell proliferation. APRIL competes with BAFF for two common receptors, TACI and BCMA, and also binds proteoglycans. Like BAFF, APRIL also appears to have anti-apoptotic effects, enhances B cell and plasma cell survival and maintenance and shares other common effects.