THZ1 Dihydrochloride is primarily used in research settings to study its role as a potent and selective inhibitor of CDK7, a cyclin-dependent kinase. Its application is significant in cancer research, where it helps to understand the mechanisms of transcriptional regulation and cell cycle control. By inhibiting CDK7, this compound is utilized to investigate its effects on cancer cell proliferation and survival, particularly in models of triple-negative breast cancer and small cell lung cancer. Additionally, it serves as a valuable tool in exploring potential therapeutic strategies targeting transcriptional dependencies in various malignancies.