As depicted in Figure 4, the cGAS-STING pathway exerts a dual regulatory role in the breast cancer microenvironment: on one hand, it activates dendritic cells (DCs) and CD8+ T cells; on the other hand, its immunostimulatory effects can be counteracted by immunosuppressive cells such as Tregs and MDSCs. This evidence concerns the gene STING1 and breast cancer.