Comparison of tumour and normal mRNA expression using TCGA GDC data (n = 1284) revealed no significant difference for METTL3 or CBLL1 expression, whereas METTL14 expression was lower in tumour tissue compared with normal breast tissue (p < 0.0001) (Supplementary Fig. 1B-D). Here, METTL3 is linked to neoplasm.