Biallelic inactivation of SMARCB1 is found in over 90% of several aggressive pediatric malignancies including malignant rhabdoid tumor of the kidney (MRTK), atypical teratoid rhabdoid tumor (ATRT), and renal medullary carcinomas (RMC)5,6. The gene discussed is SMARCB1; the disease is rhabdoid tumor of the kidney.