CCL4 （macrophage inflammatory protein-1β, MIP-1β） is a CC chemokine that belongs to the group of inflammatory chemokines and acts as a chemoattractant for different immune effector cells such as immature DC, TH1 T cells, NK cells and monocytes. In contrast to CCR7 that is expressed on mature DC and naive T-cell subsets, the CCL4 receptor CCR5 is expressed on immature DC and TH1-polarized T cells. CCL4 can activate chemokine receptor CCR5, which is involved in diverse immune responses. Among the diverse chemokines, CCL4 and its receptor CCR5 have been a focus of research on HIV. CCL4 is also secreted by CD8 + T cells and attracts monocytes, natural killer cells, and other immune cells.