MRPL4 and COVID-19: Notably, an sgRNA targeting a locus (yellow highlighted) near rs74956615 significantly repressed the expression of RAVER1 but no other lung epithelial genes expressed in A549 cells, including MRPL4, ZGLP1, FDX2, ICAM3 and TYK, located at chromosome 19p13.2 (≥1.5-fold, P=0.0050, two-sided Student's t-test; Fig. 2b), suggesting that the locus with rs74956615 influences the expression of RAVER1 and in turn impacts the development of critical illness in COVID-19.