Specifically, recurrent Signal transducer and activator of transcription 3 (STAT3) mutations in the Src‐homology 2 (SH2) domain have been reported in approximately 40% of both T‐ and NK‐LGL leukemia patients, with Y640F and D661Y the most commonly reported.5, 7, 9, 10, 11. The gene discussed is STAT3; the disease is leukemia.