Impaired ALCAM expression is associated with induced ER+ breast cancer cell apoptosis and autophagy56, and down-regulating ALCAM expression sensitizes ER+ breast cancers to Tamoxifen treatment57, suggesting the therapeutic potential of down-regulating ALCAM in ER+ cancers which is consistent with its relatively higher expression in such tumor subtypes (Fig. 7). This evidence concerns the gene ESR1 and breast carcinoma.