METTL3 and breast cancer: Similarly, XBP1 has been shown to upregulate methyltransferase-like 3 (METTL3) and METTL4 to enrich m6a methylation and thus promote the mRNA stability of Calcium Binding And Coiled-Coil Domain 1 (CALCOCO1) and p62 (known ER-phagy regulators) in breast cancers [181].