EPO and COVID-19: By T4, both groups converged to similar ERI levels (13.5, 8.4–18.4 U/kg/week/g/d for CoV2 patients and 13.6, 8.9–19.3 U/kg/week/g/dL for nonCoV2 patients), suggesting a delayed recovery in erythropoietin responsiveness among COVID-19 patients.