NOTCH1 mutations were detected in 55% of T-LBL and relative to better EFS and OS.13 N/Fmut was found in 27 of 52 patients with adult T-LBL and confirmed as a favorable prognostic indicator.15 Besides, immunohistochemistry of NOTCH1 intracellular domain could help differentiate T-LBL from thymoma.16 The gene discussed is NOTCH1; the disease is thymoma.