STING1 and neoplasm: Specifically, we identify interferon-simulated, Ly6Ehi neutrophils—induced by tumor-intrinsic STING-signaling—as a tumor-infiltrating and blood-borne predictive biomarker for immunotherapy response in both mice and humans (AUC ≈ 0.9, humans) across a multitude of additional models and cancer types, respectively (Figures 1B and 1C).