In summary, endogenous protein inhibitors of PP2A, SET and CIP2A are physiologically important proteins in the cells, and the overexpression of SET and CIP2A induces strong inhibition of PP2A activity, resulting in tumor promotion and progression of human cancers, as shown by the okadaic acid pathway in rodent carcinogenesis experiments (Fig. 4). The gene discussed is CIP2A; the disease is cancer.