CXCL9 and neoplasm: IMER employs a tiered biomarker strategy to monitor TME dynamics: (i) serum biomarkers (HMGB1 for tumor lysis, CXCL9/CXCL10 for DC migration, and sST2 for toxicity risk) provide real-time response assessment [113, 150, 151]; (ii) spatial biomarkers (multiplex IF/spatial transcriptomics) reveal intratumoral heterogeneity, with interface PD-L1 expression predicting ICI efficacy and TCF1+ memory T cells indicating durable responses [152–154]; and (iii) liquid biopsies (ctDNA clearance, TCR clonality) enable early identification of nonresponders and irAE-prone patients [155–157].