Recently, we found that expression of KDM2A is inversely correlated with the level of the tumour suppressor tet-eleven translocation 2 (TET2), a DNA demethylase, in breast cancer.15 Our data demonstrated that KDM2A suppresses TET2 expression via transcriptional repression, which leads to the reduction of two TET2 target genes, E-cadherin and epithelial cell adhesion molecule, and the increase of cancer invasiveness. The gene discussed is KDM2A; the disease is cancer.