title: Clonal inheritance versus variability of rRNA gene activity in human fibroblasts.
mesh_terms: D002999:Clone Cells; D005347:Fibroblasts; D014644:Genetic Variation; D006801:Humans; D009697:Nucleolus Organizer Region; D012335:RNA, Ribosomal / Q000235:genetics*
chemical_list: D012335:RNA, Ribosomal