CDK9 and cancer: In addition, Yao et al., found that oroxylin A (OA) inhibited the activity of cyclin-dependent kinase 9 (CDK9) in HepG2 cells, which in turn inhibited pinK1-PRKN-mediated mitochondrial autophagy, induced the accumulation of damaged mitochondria in HepG2 cells, suppressed the growth of HCC cells, and reduced the resistance of HCC to sorafenib and other anti-cancer drugs [60].