The expression of the pyroptosis-related genes AIM2, CASP1, CASP3, CASP6, CASP8, CASP9, GSDMA, GSDMC, GZMB, IL6, NLRP3, NLRP7, NOD1, NOD2, SCAF11, and TIRAP was significantly higher in blood leukocytes of COVID-19 patients, indicating that the level of pyroptosis was significantly increased (Figure 1A). Here, CASP9 is linked to COVID-19.