The immunofluorescence and western blotting results showed that the RARb antagonist LE135, PPARg antagonist T0070907, LXR agonist T0901317 and Rev-Erba agonist SR9011 reduced the KI-67 and PCNA protein levels in all three osteosarcoma cell lines (Fig. 3A–C). This evidence concerns the gene PCNA and osteosarcoma.