In conclusion, this study identified several potential molecular targets that might contribute to the MTX resistance in osteosarcoma cells, such as GADD45A, AARS, AURKA, AURKB, CENPA, CCNB1, CCNE2, and CDK1, which may function via aminoacyl-tRNA biosynthesis pathway, cell cycle pathway, or p53 signaling pathway. Here, GADD45A is linked to osteosarcoma.