PTP1B was originally considered to play a tumor suppressor role counteracting activated tyrosine kinases, such as Bcr-Abl, β-catenin, and epithelial growth factor receptor13, 14, 15; however, a growing body of evidence also supports the notion that PTP1B is actively involved in promoting carcinogenesis by interacting with several oncogenic substrates, including HER2/Neu, ERK1/2, p62Dok and Src8, 16, 17. The gene discussed is PTPN1; the disease is neoplasm.