Several genes with hypermethylated promoters are established tumor suppressor genes such as DLC1 and CASP3, while examples of hypomethylated genes with cancer-promoting functions include MADCAM1 and CXCR3. Our overall analyses of differentially methylated genes associated with invasive breast cancer indicates extensive dysregulation of cancer-related genes whose altered promoter methylation may have important functional consequences contributing to the invasive cancer phenotype. This evidence concerns the gene MADCAM1 and cancer.