(Fig 3B and 3C) Furthermore, overexpression of mutant PTPRD in HNSCC cells without endogenous PTPR family mutations (PE/CA-PJ34clone12) leads to increased pSTAT3 (Y705) expression relative to PTPRD wild-type-overexpressing cells for nearly all mutations tested. The gene discussed is PTPRR; the disease is head and neck squamous cell carcinoma.