CCL2 and neoplasm: Furthermore, we observed that M2 macrophage markers (CD68, CD301, and ARG1) were positively correlated with the expression of MMP9, MMP2, and CYCLIND1 in human PAs (Figure 2E), yet the expression of M1 macrophage markers (RANTES, TNF-α, and MCP1) did not show the same trend (Figure S2).These findings indicated that infiltration of M2-like TAMs are positively correlated with tumor invasion in PAs.