ACE2 and COVID-19: Furthermore, we analyzed ADAM17 mRNA and ACE2 mRNA from 994 samples through the TCGA dataset and found that ADAM17 mRNA level was 10-fold higher than ACE2 (Figure 4D), suggesting that ADAM17 might play a critical role in SARS-Cov-2 entry in patients of the lungs, which was supported partially by a systematic review that showed the level of malignancy in lung cancer patients correlated with the likelihood of having COVID-19 (43).