CASP9 and pneumocystosis: After transfection of miR-17 mimic, no difference was observed in the mRNA expression of P53, cyt C, and caspase 9 between the mimic group and the mimic NC group; The PCP groups(250 and 62.5 μg/mL) significantly promoted the mRNA expression of P53 (P < 0.01); The PCP group of 125 μg/mL significantly promoted the mRNA expression of P53 (P < 0.05) (Figure 7A); The PCP groups of 250 and 125 μg/mL significantly promoted mRNA expression of cyt C (P < 0.001) (Figure 7B); The PCP groups of 250 μg/mL−62.5 μg/mL significantly promoted the expression of mRNA of caspase 9 (P < 0.001) (Figure 7C).