PTPN1 and neoplasm: PTP1B has been reported to exert its oncogenic activities through the activation of the nonreceptor tyrosine kinase Src (Zhang and Yu, 2012), which can enhance Ras/Raf/ERK/PI3K/mTOR pathway signaling and thereby promote tumor cell proliferation and metastasis (Penuel and Martin, 1999; Bollu et al., 2017).