Enteropathy-associated T-cell lymphoma (EATL) is characterized by frequent mutations in the JAK/STAT pathway, most commonly involving JAK1 and STAT3 and rarely JAK3, STAT5B, TYK2, or SOCS1. KMT2D and TET2 are also frequently mutated in EATL [17]. The gene discussed is JAK1; the disease is enteropathy-associated T-cell lymphoma.