Four out of the 9 regulators including protein virilizer homolog (KIAA1429), methyltransferase-like 3 (METTL3), Wilms’ tumor 1-associated protein (WTAP), and YTH domains of Homo sapiens (YTHDC1) were significantly differentially expressed in osteosarcoma samples with metastasis compared with those without metastasis in the testing set as shown in Figure 1D. This evidence concerns the gene METTL3 and osteosarcoma.