The increased risk of SPCs in heritable retinoblastoma has been well known for many decades, and the increased incidence of SPCs in our complete nationwide cohort of patients with heritable retinoblastoma supports the findings of previous studies.7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22 The risk is caused by constitutional RB1 pathogenic variant, compromising tumor suppressor function. This evidence concerns the gene RB1 and neoplasm.