PPIA and HIV-1 infection: For initial experiments to simultaneously assess the role of cell-type, CypA and cell-cycle in HIV-1 infection and its inhibition by MX2, we generated HeLa and HT1080 cell lines that expressed MX2 in a doxycycline-inducible manner and challenged these cells with HIV-1WT, derivatives encoding CA mutations (some of which had been selected for MX2-resistance), and other lentiviruses (Figure 1 and Figure 1—figure supplements 1 and 2).