PDGFRA and osteosarcoma: In contrast, models of osteosarcoma were more reliant upon genes involved in “skeletal system morphogenesis”, including PDGFRA, ACVR2B, TGFBR2, DLG1, FGFR1, and FGFR2 (Su et al., 2008) (Gene Ontology enrichment p < 0.001 after correcting for multiple hypothesis testing, Berriz et al., 2009; Figures 2A and 2B).