IGF1 and osteosarcoma: There is also evidence for GLUT1 isoform expression in human osteosarcoma cell lines (Fan et al., 2010; Cifuentes et al., 2011) and rodent osteoblastic (PyMS) cells in which glucose transport is regulated by parathyroid hormone and insulin-like growth factor 1 (IGF-1; Zoidis et al., 2011).