Cell-free infection with HTLV-1 is very inefficient [95]; efficient transmission depends on cell-to-cell transfer through direct cell contact, polarization of the microtubule-organizing center (MTOC), which is triggered by Tax, and the formation of a virological synapse, which allows the entry of viral particles, viral proteins and genomic RNA into fresh target cells [96]. The gene discussed is CNTN2; the disease is infection.