In a study comparing the gene expression of 22 human osteosarcoma tumors to 5 normal human osteoblasts, osteosarcoma tumors had increased expression of RECQL4, SPP1, RUNX2, and IBSP and decreased DOCK5, CDKN1A, RB1, P53, AND LSAMP compared to normal osteoblasts. This evidence concerns the gene RB1 and osteosarcoma.