FPR1 and hepatocellular carcinoma: The location of FPR1+ macrophages close to SAAs+ hepatocytes in the invasive zone was observed in multiplexed IF staining of validation cohort 4, which included specimens of both primary liver cancer (HCC, 7; ICC, 20) and liver metastasis from different cancers (colorectal cancer, 5; pancreatic cancer, 4; lung cancer, 5; gallbladder carcinoma, 5; gastric cancer, 5; ovarian cancer, 5) (Fig. 5g, h; Supplementary information, Fig. S7a–f).