SMARCB1-deficient cancers are characterized by biallelic loss and inactivation of this tumor suppressor gene; this is particularly noted in rare and aggressive childhood cancers such as rhabdoid tumor of the kidney, atypical teratoid rhabdoid tumors, synovial sarcoma, and myoepithelial carcinomas of the lung [21,22,23,24,25,26]. This evidence concerns the gene SMARCB1 and rhabdoid tumor of the kidney.