RB1 and retinoblastoma: To further support our hypothesis that the germline variant in the RB1 gene as an intrinsic risk factor is sufficient for the development of RB and multiple SMNs even in the absence of extrinsic risk factors, we performed an extensive literature search of the Pubmed database for articles published through August 2024 to identify case reports of patients with RB who developed at least one SMN and EWS being at least one of these SMNs (Table 1).