SMARCB1 and T-cell prolymphocytic leukemia: SMARCB1 has key roles in human lymphocyte development and function21, but little is known about its role in lymphoma pathogenesis, despite SMARCB1 deletions and mutations described in T-cell prolymphocytic leukemia and cutaneous T-cell lymphoma22–24 and, recently, biallelic SMARCB1 loss was also associated with aggressive hematopoietic malignancy25.