Lysine demethylase 2A (KDM2A) was firstly identified as a novel Jumonji-C (JMJC) domain-containing proteins that exhibited H3K36 demethylase activity.14 Our previous study demonstrated that KDM2A was frequently overexpressed in breast tumor tissues and this demethylase upregulated Jagged1 to activate the Notch signaling pathway to promote cancer stemness and angiogenesis.15 Interestingly, we found that knockdown of KDM2A induced a significant increase of 5′-hmc level in genomic DNA suggesting a potential role of KDM2A in the regulation of DNA methylation. Here, KDM2A is linked to breast neoplasm.