Comparison of molecular abnormalities between HTLV-1–infected T cells and transformed ATL cells. Many aspects of the ATL cell phenotype share common characteristics with that of untransformed HTLV-1–infected T cells expressing viral proteins, including Tax. Tax was shown to induce the majority of molecular changes observed in HTLV-1–infected cells, most of which are preserved in ATL cells that do not express Tax. Thus, this phenomenon is sometimes referred to as the signature of Tax. CARD11, caspase recruitment domain-containing protein 11; GPR183, G-protein coupled receptor 183; NRXN3, neurexin-3; PLCG1, phospholipase C, γ 1; PRKCB, protein kinase C β.