CDK9 and cervical cancer: In cervical cancer cell lines, Caspase-8 negatively regulated the phosphorylation of CDK9 at Thr186 (pCDK9), thereby compromising its activation and the activity of the CDK9/CyclinT1 complex—P-TEFb (Positive Transcription Elongation Factor b) in phosphorylating the Ser2 residue at the C-terminal domain (CTD) of RNA polymerase II (RNAPII), thereby altering global transcription.