Evidence has also shown the formation of gap junctions between astrocytes and tumor cells, which allows for the passage of an intracellular second messenger 2′3′-cyclic GMP-AMP (cGAMP), which activates the STING pathway in astrocytes and promotes the expression of interferon α (IFNα) and TNFα to further facilitate tumor growth [142]. The gene discussed is TNF; the disease is neoplasm.