CD8A and HIV infectious disease: The greatest changes in expression were demonstrated in the case of SIRT6, the levels of which increased significantly after the use of cART, thus proving the beneficial effect of the implemented antiretroviral therapy on the level of this enzyme as well as the therapy’s relationship with HIV viral load, LT CD8+ count, and plasma levels of SIRT6, which may, in turn, reflect the body’s immune response to HIV infection.