After being adjusted with multinomial logistic regression, only absence of HAART (AOR, 95% CI: 2.3 (1.3, 4.7), P < 0.05), low CD4 T cell count <350 cells/μL (AOR, 95% CI: 3.8 (1.6, 9.4), P < 0.05), and infection with intestinal parasites (AOR, 95% CI: 2.7 (1.1, 7.2), P < 0.05) were significantly associated with anemia (Table 3). The gene discussed is CD4; the disease is anemia (phenotype).