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. The gene discussed is CGAS; the disease is breast cancer.