In this study, we examined the relationship between degree of anaplasia and a range of these factors, including chromosome 1q, 6p, 9q, and 16q status; automated digital measurement of 33 different tumor cell size and staining characteristics; mutations in RB1, CREBBP, NSD1, and BCOR; amplification of MYCN; and extraocular spread of retinoblastoma. This evidence concerns the gene RB1 and retinoblastoma.