GJA1 and neoplasm: It has been shown that the formation of gap junctions between astrocytes and tumor cells through connexin 43 (CX43), allows the passage of cyclic guanosine monophosphate‐adenosine monophosphate, which activates the stimulator of interferon genes (STING) pathway in astrocytes and promotes expression of IFNα and TNFα to further facilitate brain metastatic growth.155