Furthermore, the HIV-1 transactivator protein Tat, one of the retroviral proteins identified as a key immunomodulator in the pathogenesis of AIDS, interfered with the IFN-γ receptor signaling pathway at the level of STAT1 activation, possibly via Tat-dependent induction of SOCS2 activity induced by HIV infection, again pointing towards SOCS2 as an important modulator of immune responses [16]. Here, TAT is linked to HIV infectious disease.