Tumor-intrinsic suppression: ENPP1 overexpression in breast cancer generates adenosinergic metabolites that upregulate haptoglobin (HP), promoting polymorphonuclear myeloid-derived suppressor cell (PMN-MDSC) infiltration and neutrophil extracellular trap (NET) formation, ultimately facilitating locoregional relapse post-surgery/irradiation. Here, HP is linked to breast cancer.