While an increase of KDM3A is concomitant with a reduced H3K9me2/3 during breast tumorigenesis, KDM3A facilitated the activation of genes implicated in breast cancer as MYC, PAX3, Cyclin D1, MMP-9, S100A4, and JUN, thereby enhancing the proliferation and motility of breast cancer cells (136–138). The gene discussed is CCND1; the disease is breast cancer.