HLA-B and infection: To study differences in the Gag protein of virus isolates obtained from HLA-B*57/58:01 progressors and LTNPs that may explain the differences in replication kinetics, we compared Gag sequences (positions 1-364) obtained from various time points during the course of infection (Table 1 and Table S1) using the Sequence Harmony (SH) algorithm [29]–[31].