IGF1 and osteosarcoma: IGF-1 can act by activating the PI3K/AKT pathway through activation of the IGF-1R located on the cell surface, and therefore by affecting IGF-1R can also affect activation of the PI3K/AKT pathway.It was found that miR-133a, miR-133b (Figure 6A), and miR-100 can partially block this pathway, and miR-133a, miR-133b, and miR-100 can then target IGF-1R in human osteosarcoma cells to inhibit the activation of PI3K/AKT pathway and thus inhibit apoptosis, proliferation, invasion, metastasis, migration, and chemoresistance of osteosarcoma (158, 194, 198).