The recruitment of TAMs to the tumor site is mediated by various chemokines and cytokines produced by both tumor cells and stromal cells. Key chemokines include CCL2 (MCP-1), CCL5 (RANTES), and CSF-1 (M-CSF). These signals attract monocytes from the bloodstream, which then differentiate into macrophages upon entering the tumor microenvironment. Once differentiated, these macrophages can be further polarized by local signals to either an M1 or M2-like phenotype.
