Androgen-receptor (AR) gene copy increase, steroid hormone-mediated pathways, especially estrogen and AR-related pathways, DNA methylation levels of cytokeratin-related genes and other genes involved in cytoskeleton architecture, membrane trafficking, gene transcription, cell migration, invasion, adhesion, survival and growth, and sexually dimorphic breast-associated microbiota (known as the “microgenderiome”) contribute to biological sex/gender-related disparities in BC. Here, AR is linked to breast cancer.