BRCA1 and breast cancer: The largest study investigating association of the genome-wide methylation changes in pre-diagnostic blood samples with breast cancer risk (three independent cohorts of matched cases and controls: EPIC; n = 162, NOWAC; n = 168, BGS; n = 548) based on BeadChip microarray technology, did not find methylation changes at BRCA1 gene8, similarly to study by Severi G. et al.,9.