The invention relates to the compounds and methods for inhibiting the Cyclin-Dependent Kinase Inhibitor (CDKI) pathway. More particularly, the invention relates to compounds and methods for inhibiting the CDKI pathway for studies of and intervention in senescence-related and other CDKI-related diseases. The invention provides new compounds having improved solubility and/or potency, and methods for their use. In various aspects, the invention relates to the treatment of cancer. The invention provides methods for chemoprevention and prevention of tumor recurrence or metastasis. The invention further provides diagnostic techniques for treatment for certain cancer types. The invention utilizes specific inhibitors of CDK8/19 and/or measurement of CDK8 levels in a patient.
