RB1 and retinoblastoma: In fact, the differences in molecular spectra of MYCN-amplified RB1-proficient retinoblastomas compared with other retinoblastoma subtypes were very well marked at the epigenomic level, which affected a molecular network beyond CDKN2C. Epigenetic alterations are well-known cancer events with versatile impact on various stages of carcinogenesis, ranging from disruption of genomic stability to silencing of tumor suppressors and regulatory elements.32