RB1 and neoplasm: Given the dominant influence of cell cycle events in the scRNA-Seq analysis, we opted to perform an integrated scATAC-Seq analysis, which clusters cells on the basis of chromatin accessibility and is thus more likely to identify early epigenetic and transcriptional events that lead to cone precursor proliferation and unravel different clones within the tumor that are likely to arise as result of independent second lesion in addition to RB1 inactivation.