SLC6A4 and COVID-19: It has been reported that SRC [57], EGFR [58], EZH2, IL-6 [59], PTGS2 [60], PPARG [61], SLC6A4 [62], PPARA [63], ACHE [64], NR3C1 [65], ADK [66], AKT1 [67], and MTHFR [68] are closely related to the pathogenesis of COVID-19.