METTL1 and ovarian serous cystadenocarcinoma: An important well-studied regulator of m7G in mammals is methyltransferase-like 1 (METTL1), which binds to its corresponding cofactor WD repeat domain 4 (WDR4) to install m7G modifications in tRNA, miRNA, and mRNA (25, 26) while METTL1 is associated with favorable survival in patients with ovarian serous cystad enocarcinoma (27).