Majority of the breast cancers are ERα dependent (~70%) and E2 driven.43, 44 Genome-wide analysis of ERα recruitment to the target promoter post E2 treatment demonstrated a wide array of genes regulated directly or indirectly by ERα.45, 46 Notably, both the genome-wide analysis identified CASP7 as a direct target gene of ERα but its molecular regulation was not well defined. The gene discussed is ESR1; the disease is breast carcinoma.