STAT3 and T-cell leukemia: Increased eosinophils, particularly in the skin, have been associated with activation of signal transducer and activator of transcription 3 (STAT3) in CTCL T cells [47,48], and additional Janus kinase (JAK)-STAT dysfunction is frequent in CTCL, other T-cell leukemia/lymphomas, and many BIDs [49,50].