While ATRT-SMARCB1 is more frequently diagnosed, very few of these cases are inherited from a pathogenic mutation in SMARCB1 from a healthy parent.11 On the other hand, germline mutations in SMARCA4 are more common and have been shown to result in more aggressive tumor behavior, leading to worse prognosis.4 While both SMARCB1 and SMARCA4 contribute to the SWI/SNF complex, SMARCB1 has localized impact. The gene discussed is SMARCA4; the disease is neoplasm.