MRC1 and neoplasm: In the liver, M2-type macrophages expressing CD163 and CD206 produce hepatocyte growth factor (HGF), which engages the c-Met tyrosine kinase receptor on the surface of migrating tumor cells, promoting their extravasation into the liver through activation of various signalling pathways, including JAK/STAT3, MAPK, PI3K/AKT, and NF-κB 181- 183.