SMARCB1 and rhabdoid tumor of the kidney: In addition to RMC, SMARCB1 alterations are found in approximately 20% of all cancers (14, 15), and biallelic inactivation of SMARCB1 is also a universal characterizing feature of kidney malignant rhabdoid tumor (MRT) that similarly has an extremely low rate of mutation and aggressive nature of onset (16).