To investigate whether high expression levels of SRCIN1 were modulated by DNA hypermethylation of SRCIN1, we treated breast cancer cells with the DNMT inhibitor 5-aza-2′-deoxycytidine (DAC) to suppress the methylation of the SRCIN1 gene and then analyzed the SRCIN1 mRNA expression level. The gene discussed is DNMT1; the disease is breast carcinoma.