IGF1 and osteosarcoma: To determine the impact of Lnc-CLSTN2-1:1 on the cell cycle via the PI3K/AKT pathway, which contributes to the malignant biological behavior of osteosarcoma, we pretreated cells with igf-1 (PI3K /Akt agonist) and then measured the protein levels of P-AKT and cyclinD1.