CXCR4 and infection: Infection was carried out with a HIV GKO (HIV_LTR-GFP-EF1α-mKO2) dual-reporter vector pseudotyped with three different envelopes, as follows: VSV-G for amphotropic viral entry, and natural HIV envelopes LAI for CXCR4 tropism, and BaL for CCR5 tropism.