CCR6 and neoplasm: Tumor‐associated macrophages (TAMs) are considered anti‐tumor suppressors, and in HCC, TAMs can regulate kinase (ERK)/NF through extracellular signaling (the κ‐B pathway), which increases the expression of CCL20 and subsequently induces the accumulation of CCR6+ Tregs, which may lead to resistance to programmed death ligand 1 (PD‐L1) immunotherapy [38].