SMARCB1 and kidney medullary carcinoma: The established function of BCL11A is that it forms a key component of the mammalian SWI/SNF complex, a chromatin remodeling apparatus that has been implicated in 20% of all human tumors and notably aberrant in several other pediatric kidney tumors such as malignant rhabdoid tumor of the kidney and renal medullary carcinoma, both of which are characterized by biallelic inactivation of SMARCB1 (13); indeed, somatic alterations of BCL11A are noted in many different, generally adult-onset, cancers (14).