Six genes, (CD36 [40], CUEDC1 [41], LAMP3 [42], SDCBP [43], LTBP2 [44], PIP [45]), of the set of 26 differentially expressed genes with enriched or depleted binding of FOXA1 or ER in response to induction of ELF5, are implicated endocrine resistance, and nearly all genes in this set appear in one or more gene sets derived from estrogen action, breast cancer subtype or endocrine resistance. The gene discussed is ESR1; the disease is breast cancer.