HTLV-1 is the etiological agent for Adult T-Cell Leukemia which encodes a 40kDa cell-transforming oncoprotein called Tax. HTLV-1 Tax protein sensitizes cells to apoptotic cell death induced by DNA damaging agents. Constitutive Activation of TAK1 by HTLV-1 Tax-dependent Overexpression of TAB2 Induces Activation of JNK-ATF2 but Not IKK-NF-kB.