The molecular mechanisms associated with DNMT3B expression were then further investigated by comparing DNA methylation levels in high-DNMT3B-expressing tumours (DNMT3B+) versus low-DNMT3B-expressing tumours (DNMT3B−) samples in the TCGA–BRCA public dataset, which combines expression and methylome data from the same breast cancer tumours, and then confirmed in an independent cohort. Here, DNMT3B is linked to neoplasm.