CDK19 and skin papilloma: Following a skin carcinogenesis regimen with 7,12-dimethylbenz[α]anthracene (DMBA) and 12-O-tetradecanoylphorbol-13-acetate (TPA), the average number of skin papillomas per mouse was 3-fold higher in the single copy CDK11 gene mice compared to mice with two copies of CDK11.