AGER and breast carcinoma: In a mouse model of mammary carcinoma, S100A8/A9 bound to a receptor for advanced glycation end products (RAGE) on MDSCs, promoting their migration and accumulation through NF-kB signaling.42 STAT3 upregulates the S100A8/9 proinflammatory proteins, which enhances MDSCs accumulation in a feedback loop.