METTL3 and breast cancer: In this study, we used Oncomine and The Cancer Genome Atlas (TCGA) databases to jointly analyze the expression of m6A “writer” in breast cancer including METTL3, METTL14, WTAP, RBM15, RBM15B, and ZC3H13, indicating that the mRNA expression levels of METTL14 and ZC3H13 were lower in tumor samples.