NRP2 and COVID-19: In this report, we provided evidence suggesting that mdig, a potential oncogenic gene induced by several common environmental hazards 17, 42, may augment the infectivity of SARS-CoV-2 and the severity of COVID-19 through upregulating S protein receptors NRP1 and NRP2, several proteases and the genes in the pathways of glycan metabolism and inflammation (Fig. 9).