In a study using the monoclonal antibody tenatumomab across 100 patients with T/NK-cell neoplasms (75 PTCL; 25 CTCL), tenascin-C expression was observed in multiple subtypes, including ALCL, ALK-negative (n = 21), ALCL, ALK-positive (n = 19), PTCL-NOS (n = 20), MF (n = 13), AITL (n = 9), CD30+ primary CTCL (n = 6), and other subtypes (n = 12). This evidence concerns the gene ALK and mature T-cell and NK-cell non-Hodgkin lymphoma.