CASP9 and pneumocystosis: In this study, after high-throughput sequencing, it was found that miR-17 was differentially expressed during apoptosis caused by PCP and TGEV infection, so after transfection of miR-17 mimic and inhibitor, the mRNA expression of caspase 9 in the mimic group was lower than that in the NC group, but there was no significant difference (Figure 7).