In Herceptin-resistant HER2+ breast cancer, an immune-related prognostic index (IRPI) identifies suppressed type I interferon and cGAS-STING signaling as key mediators of immune escape, while combining STING agonists with the HER2-targeted ADC DS-8201 presents a promising strategy to overcome therapeutic resistance (97). This evidence concerns the gene STING1 and breast carcinoma.