cGAS‐STING signaling undoubtedly plays an important, centralized role in the immune‐mediated clearance of malignant cells; thus, several STING agonists have been developed and entered phase II clinical trials for antitumor therapy.[18] Moreover, with the advancement of nanotechnology, an increasing number of nanoparticles have been developed to activate the cGAS‐STING pathway for antitumor therapy.[34, 35, 36, 37, 38] In this study, we found that STING agonist monotherapy could effectively active the cGAS‐STING pathway in endocrine‐sensitive breast cancer to enhance antitumor immunity. This evidence concerns the gene CGAS and breast carcinoma.