▪Increased intracellular reactive oxygen species (ROS)▪Induced apoptosis preferentially in BC cells▪Changed methylation status in some of the CpG islands in BC cells (DNAJC8, POTED, and EIF1YA) and estrogen receptor‐positive BC cells (ESFR1, PRR7, CD86, DHRS7B, FDX1, CREB3, BCL‐2, and BDNF). The gene discussed is DHRS7B; the disease is breast cancer.