Meanwhile, if oscillatory gene expression in some undifferentiated cells/RPCs does not stop due to pathological events (e.g., mutations in genes regulating the stability of mRNA and proteins of genes like Notch1, Hes1, Dll1, Ascl1, Neurog2, etc.), these cells may begin retinoblastoma formation. This evidence concerns the gene NOTCH1 and retinoblastoma.