SMARCB1 and rhabdoid tumor: The role of this complex in embryonal tumors is clearly exemplified in malignant rhabdoid tumors (MRT), which are characterized by the complete loss of SWI/SNF subunit SMARCB1 (95% of cases) or SMARCA4 (5% of cases) (Lee et al., 2012; Hasselblatt et al., 2014).