PCNA and neoplasm: Immunohistochemistry and western blotting analyses (Fig. 2D,E) showed reduced protein expression of CHI3L1, PCNA, cyclin D1, Cdk 6, and MMP‐9, but the expression of cleaved caspase‐3 was increased; however, IL‐13Rα1 and IL‐13Rα2 levels were not changed in K284‐treated lung metastasis tumor tissues (Fig. 2D).