Given the great therapeutic potential of CDKs and cyclins, as well as rapid advancements in drug discovery and development, it is a prime time to scrutinize the involvement of Cyclin K in cancers and develop effective drugs against Cyclin K. Ideally, Cyclin K-targeting therapies will be used as powerful anti-cancer arsenals in the future and, one day, we can turn the devastation of cancer into a manageable chronic disease. This evidence concerns the gene CCNK and cancer.