M2 macrophage polarization refers to the process by which monocytes or macrophages adopt an anti-inflammatory phenotype in response to specific cytokines such as IL-4 and IL-10. These alternatively activated macrophages play a critical role in tissue repair, immune regulation, and tumor progression. In the M2 Macrophage Polarization Assay, human CD14+ cells are differentiated into M(0) macrophages using M-CSF, then exposed to IL-4/IL-10 to induce M2 polarization. The assay measures CCL18 secretion via ELISA and CD206 expression through high-content imaging, providing a robust platform to evaluate therapeutic candidates targeting macrophage-driven diseases like fibrosis and cancer.