The results of gender adjustment for ACE2 rs1978124 showed an association between the COVID-19 mortality rate and TC genotype (P < 0.0001, OR 1.70, 95% CI 1.38–2.09) in female and TT genotype (P < 0.0001, OR 1.28, 95% CI 1.08–1.52) in male patients (Additional file 1: Table 2). Here, ACE2 is linked to COVID-19.