SMARCB1 and cancer: As a distinct and unique type of malignant tumor, MRT has the characteristic appearance of patternless sheets of noncohesive cells with abundant cytoplasm and eosinophilic inclusions, as well as specific molecular aberrations involving SMARCB1 (hSNF5/INI1), which can be identified by a lack of staining with INI1 immunohistochemically.