Somatic mutations in genes encoding molecules involved in cytokine signal transduction, and specifically in γc associated JAK-STAT signaling, have previously been identified in NK-/T-cell lymphoma (NKTCL), angioimmunoblastic T-cell lymphoma (AITL), T-PLL, HSTL, SS, and T-LGL subtypes of PTCL [5, 8, 12, 42, 47, 53]. The gene discussed is SOAT1; the disease is T-cell large granular lymphocyte leukemia.