TYK2, a member of the Janus Kinase family of proteins has been shown to play a role in immune surveillance and host response in the setting of infection, autoimmune disorders, and malignancy.22, 23, 24, 25 More recent cancer genomic studies have identified activating mutations in TYK2 within cancer cells, implicating a cell intrinsic role for TYK2 in promoting cancer progression.9, 25, 26, 27 Based on these genomic studies, we have begun to explore the role of TYK2 in MPNST pathogenesis. This evidence concerns the gene TYK2 and cancer.