CDK1 and cancer: The main rationale of testing pan-CDK inhibitors in cancer patients lies in the ability of these molecules to inhibit both cell-cycle-driving CDKs (such as CDK1 and 2) and transcription-driving CDKs (such as CDK7 and 9), which, in the latter case, causes the loss of short-lived mRNAs coding for anti-apoptotic proteins (Blagosklonny, 2004).