Apoptosis is induced by certain cytokines including TNF and Fas ligand in the TNF family through their death domain containing receptors. TNF-related apoptosis-inducing ligand (TRAIL or Apo2L), a member of this family, activates apoptosis in a variety of tumor cell lines by signaling through the death receptors, DR4 and DR5. Bioymifi directly activates DR5 (Kd = 1.2 μM; IC50 = 2 μM), inducing DR5 clustering, which leads to the initiation of FADD/caspase-8-dependent apoptosis in various cancer cells.