Results: Recurrent alterations included FAT1 (28.2%), KMT2D (19.2%), TP53 (13.5%), JAK3 (11.5%), and SETBP1 (11.5%), highlighting the role of Wnt signaling, epigenetic dysregulation, the p53 pathway, and JAK/STAT signaling in MF pathogenesis. The gene discussed is JAK3; the disease is mycosis fungoides.