GJA1 and breast cancer: The role of GJA1 has been identified in breast cancer bone metastasis (Wang et al., 2018); its interactions with p21-activated protein kinase 1 to activate mitogen-activated protein kinase (MAPK) signaling in HeLa cells (Aasen et al., 2019) and its upregulation leading to micro-metastasis and tumor vasculature in tumor cell–endothelial cell contact areas (Elzarrad et al., 2008) lead to evidence of GJA1 as a potential target.