Among those with HCV coinfection, CD4 < 100 was associated with a HR for incident anemia of 10.20 (95% CI 8.01, 12.98), while for those without HCV coinfection, the HR was 5.01 (95% CI 3.39, 7.42; p-value for low CD4-HCVcoinfection interaction =0.001; Supplemental Table 2). This evidence concerns the gene CD4 and anemia (phenotype).