CCL17 and cancer: However, Morimura et al., suggested that a high level of CCL17, known as thymus and activation-regulated chemokine, may work as a “safety-net” to reduce the risk of malignant tumors and positively contributes to tumor immunity via decreasing myeloid-derived suppressor cells in the Th2-dominant environment in AD patients (Morimura et al., 2021).