To assess whether the above genetic variations affected gene expression levels of m6A regulators in breast cancer patients, we first compared the mRNA levels between 112 paired breast cancer and adjacent normal samples based on TCGA data, and found that most m6A regulatory genes were significantly different in breast cancer and normal samples (p < 0.05), except for YTHDC2 (p = 0.083) and ALKBH5 (p = 0.092, Figures 2A, B). Here, ALKBH5 is linked to breast cancer.