Cholecystokinin has been found to be a potential target for the treatment of various conditions including pancreatic cancer, pancreatitis, and gastrointestinal disorders. CDK7 (cyclin-dependent kinase 7) is an enzyme that is a key regulator of the cell cycle and gene transcription. It functions as a component of the Cdk-activated kinase (CAK) and transcription factor IIH (TFIIH) complexes. CDK7 phosphorylates other CDKs to promote cell cycle progression and phosphorylates RNA polymerase II to initiate gene transcription. CDK7 is often overexpressed in cancer due to its role in regulating cell proliferation. Hence CDK7 inhibitors have been researched in clinical trials as they are responsible for cell cycle arrest, apoptosis, and antiproliferative activities. This review particularly focuses on various synthetic and naturally occurring CDK7 inhibitors and their role in preventing various cancers including breast cancer, leukemia, hepatoma or cancer of liver and so on.