RRS1 and neoplasm: The tumor suppressors TP53 and RB and the oncogenes MYC and KRAS have been shown to mainly modulate the early steps of ribosome biogenesis (i.e., rDNA transcription), whereas other factors such as nucleolin, RRS1, pescadillo, or BOP1 mostly alter the late stages of ribosome biogenesis (i.e., pre-rRNA cleavage and ribosomal subunits’ maturation).