To further understand the mechanism behind this reactivation of ERα in TNBC cells, we performed time-dependent ChIP analysis to investigate combined resveratrol and pterostilbene-induced enrichment of transcriptional active chromatin markers such as acetylated-histone H3, acetyl-H3K9 and acetyl-H4 in ERα-negative MDA-MB-157 and HCC1806 breast cancer cells. This evidence concerns the gene ESR1 and breast carcinoma.