PKMYT1 and neoplasm: PKMYT1 (membrane-associated tyrosine- and threonine-specific CDC2-inhibitory kinase) is a negative regulator of CDK1 which has shown activity in tumours with CCNE1 amplification, FBXW7 and PPP2R1A mutations [322] and is already being evaluated in combination with other compounds such as chemotherapy [323].