Scientists at Orion Genomics and other labs, including Cold Spring Harbor, have used microarrays in a genome-wide screen to look for epigenetic biomarkers for early stage detection of breast cancer. In the study, published yesterday in PLoS ONE, they found about 200 loci that were differentially methylated, and then went on to validate these in 230 clinical samples. The differential cytosine methylation events, they write, were independent of patient age, tumor stage, estrogen receptor status, or family history of breast cancer.