In various cancer cell lines, including those of breast, lung, colorectal, and cervical cancers, PRMT6 has been found to inhibit the expression of cyclin-dependent kinase inhibitors (CKI) such as p21cip1/waf1, p27kip1, and p18ink4c, or to mitigate the association of p16ink4a with CDK4. Here, CDK4 is linked to cancer.