In contrast, miR-22 (185), miR-29b (187), miR-100 (194), miR-142 (199), miR-497 (200), miR-340-5p (208) and other microRNAs related to PI3K/AKT pathway showed bottom expression, and by promoting their expression, the sensitivity of osteosarcoma cells to CDDP could be improved. The gene discussed is PIK3CA; the disease is osteosarcoma.