IFITM1 and infection: Pretreating cells with IFNα shows ~ 7 fold inhibition of infection in the control NTC cell pools (Figure 4B and C) while IFN-mediated inhibition of HIV was significantly lower in MxB, TRIM5alpha and IFITM1 KO lines than in NTCs pools (Figure 4B; MxB_1 = 2.6 fold, MxB_2 = 2.5 fold, TRIM5_1 = 3.9 fold, TRIM5_2 = 4.8 fold, IFITM1_1 = 4.7 fold, IFITM1_2 = 6 fold and IFITM1_3 = 4.3 fold in Figure 4C; p < 0.05).