Among placebo-controlled trials, the significant reduction in hepcidin by HIF-PHIs was observed in all subgroups, and such effect was strengthened in DD-CKD patients (MD, −56.24; 95% CI, −85.69 to −26.78; I2 = 76.73%) and in trials with short follow-up (MD, −44.36; 95% CI, −57.39 to −31.32; I2 = 78.44%) (Table 3). The gene discussed is HAMP; the disease is chronic kidney disease.