TC-PTP deficiency in mouse epidermis led to a significant decrease in apoptosis induced by the carcinogen 7,12-dimethylbenz [a]anthracene (DMBA) and a significant increase in epidermal thickness and hyperproliferation following treatment with the tumor promotor 12-O-tetradecanoylphorbol-13-acetate (TPA). Here, PTPN2 is linked to neoplasm.