ERBB2 and posterior cortical atrophy: In addition to activation of WNT signaling via the androgen/AR-WNT7B pathway, Ni et al. showed that similar to PCa, AR and WNT/β-catenin signaling also cooperated functionally; in this case, β-catenin cooperated with AR to promote the progression and maintenance of ER−/HER2+ BCa cells by upregulating HER3, which encodes a key co-receptor of HER2 in HER2+ BCa [297].