The present study aimed to examine the associations between androgen receptor (AR) and forkhead box A1 (FOXA1) and to investigate clinicopathological features and survival according to both biomarker status in estrogen receptor (ER)-positive breast cancers using in vitro study, patient cohort data, and the cBioPortal for Cancer Genomics and Kaplan-Meier Plotter websites. The gene discussed is ESR1; the disease is breast cancer.