However, there are two major molecular differences described for Tax-1 and Tax-2: (1) Tax-1 harbors a postsynaptic density protein (PSD95), Drosophila disc large tumor suppressor (DlgA), and zonula occludens-1 protein (ZO-1) (PDZ) binding motif (PBM) at its C-terminus; the PBM is essential for the interaction of Tax-1 with host cell factors regulating cell cycle progression and tumor suppression [20,21]. The gene discussed is CNTN2; the disease is neoplasm.