Malignant rhabdoid tumors, including AT/RTs, are characterized by genetic alterations affecting the SMARCB1 (also known as hSNF5 and INI1) locus in chromosome 22q11.2 or, rarely, the SMARCA4 locus in chromosome 19p13.2 [5]. The gene discussed is SMARCB1; the disease is rhabdoid tumor.