Figure 1.

Role of chemokine C‐C motif chemokine 2–C‐C chemokine receptor type 2 (CCL2‐CCR2) signaling in cancer progression. CCL2 is secreted by cancer cells and surrounding stromal cells. It induces tumor cell proliferation at the primary tumor site, and CCR2⁺ myeloid cells attracted by CCL2 suppress immune‐mediated killing of tumor cells. CCL2 also promotes tumor cell migration and invasion into the surrounding ECM followed by tumor cell intravasation into the circulation. The subsequent dissemination of cancer cells is directed by a chemotactic gradient of CCL2 toward potential sites of metastasis. CCL2 and CCR2⁺ cells then promote tumor cell extravasation and colonization and growth at such metastatic sites