TMPRSS2 and COVID-19: The MAF of the T allele in TMPRSS2 was highly enriched in our cohort (0.388) and in East Asians (0.362) as compared with in Europeans (0.236) and Africans (0.287) as reported in the 1000G database, a database of population genetic variations (Figure 2A).We also found that the MAF of the T allele in the patients with moderate COVID-19 symptoms tended to be lower than that in the noninfected close-contact group and in the patients with asymptomatic to mild symptoms (0.334 vs. 0.388 or 0.383; Figure 2A).