STING1 and liver cancer: Furthermore, endothelial Sting activation by Cgas cells-derived CM was dramatically weakened after Lrrc8c knockdown, as shown by decreased phosphorylation of Sting and Tbk1, as well as Ifnβ and ISGs expressions (Fig. 5f, g), together suggesting that cGAMP produced by liver cancer cells is secreted out of the cell through LRRC8C channels, thereby activating STING of endothelial cells.