Different from other CDKs, in addition to regulating the cell cycle, CDK7 also plays an important role in interfering with transcription primarily by phosphorylating RNA polymerase II and transcription factors, which was confirmed in the study of CDK7 small molecule inhibitors in a variety of cancer types, including breast, lung, neuroblastoma and leukaemia.19 However, the challenging question of how CDK7 activity is integrated into transcription regulation remains largely unanswered. This evidence concerns the gene CDK7 and cancer.