Among veterans with HIV/HCV coinfection, decompensated liver disease (HR (95% CI) 2.33 (1.98–2.74)), CAD (1.74 (1.32–2.28)), CKD (1.62 (1.36–1.92)), anemia (1.58 (1.31–1.89)), COPD (1.57 (1.26–1.95)), cancer (1.52 (1.23–1.87)), and age (1.34 (1.21–1.49) for every 10-year-older age) were predictors of higher risk of mortality, while HCV treatment (0.41 (0.27–0.63)), CD4 count (0.90 (0.87–0.93) per 100 cells/μL higher count), and Black race (0.72 (0.60–0.87)) were associated with significantly lower risk of mortality (Table 3). The gene discussed is CD4; the disease is anemia (phenotype).