CDK1 and neoplasm: Flavopiridol (FLA) (also called alvocidib), a pan-CDK inhibitor (CDK1/2/3/4/6/7/9) [23], has shown anti-tumor effects and has been used in clinical trials for some solid tumors [24] and hematological malignancies, including chronic lymphocytic leukemia [25,26], AML [27,28,29], refractory multiple myeloma (clinicalTrials.gov, NCT00047203), and lymphoma (clinicalTrials.gov, NCT00445341).