CCL22 and cancer: For example, intratumoural C-C motif chemokine 22 (CCL22) is induced in tumor-infiltrating dendritic cells through interleukin-1 alpha (IL-1α) secreted by cancer cells; the accumulation of CCL22 induces the recruitment of regulatory T cells through the expression of CC chemokine receptor 4 (CCR4) and these tumor-infiltrating Tregs suppress local effector T cell responses (57).