Recently, THZ1, a potent irreversible inhibitor that is selective for CDK7, was identified and has been evaluated against blood cancers, neuroblastoma, small-cell lung carcinoma, triple-negative breast cancer and esophageal squamous cell carcinoma.11, 12, 13, 14, 15 These studies include bioinformatics analyses on the effects of THZ1 on transcription profiles driven from super enhancers; however, there is almost no information about how THZ1 induces tumor cell death by inhibiting CDK7. Here, CDK7 is linked to small cell lung carcinoma.