CXCR4 and infection: Genotypic co‐receptor analysis, using Geno2pheno and the settings recommended for CRF02_AG infections 43 predicted exclusive CCR5 usage for all studied URFs, whereas PhenoSeq, using settings optimized for subtype A and CRF02_AG, predicted CXCR4 tropism for 4/18 URF viruses (Table 2).