Recent studies have demonstrated that ACE1 I/D polymorphism could have a significant role in the prognosis of COVID-19, but these results are controversial (Delanghe et al., 2020a; Bellone and Calvisi, 2020; Saadat, 2020; Yamamoto et al., 2020; Hubacek et al., 2021). The gene discussed is ACE; the disease is COVID-19.