Chemokine (CC motif) receptor (CCR)2+ monocytes and triggering receptor expressed on myeloid cells (TREM) 2+ Mφ in the TME can terminally differentiate to matrix metalloproteinase (MMP)9+ TAMs to promote the progression of HCC by stimulating the peroxisome proliferator-activated receptor (PPAR)γ signal (Lu et al., 2022). Here, CCR2 is linked to hepatocellular carcinoma.