Chemokine (C-C motif) ligand 3 (CCL3) also known as macrophage inflammatory protein 1-alpha (MIP-1-alpha) is a protein that in humans is encoded by the CCL3 gene.

CCL3 is a cytokine belonging to the CC chemokine family that is involved in the acute inflammatory state in the recruitment and activation of polymorphonuclear leukocytes[4] through binding to the receptors CCR1, CCR4 and CCR5.

Sherry et al. (1988) demonstrated 2 protein components of MIP1, called by them alpha (CCL3, this protein) and beta (CCL4).

CCL3 produces a monophasic fever of rapid onset whose magnitude is equal to or greater than that of fevers produced with either recombinant human tumor necrosis factor or recombinant human interleukin-1. However, in contrast to these two endogenous pyrogens, the fever induced by MIP-1 is not inhibited by the cyclooxygenase inhibitor ibuprofen and CCL3 may participate in the febrile response that is not mediated through prostaglandin synthesis and clinically cannot be ablated by cyclooxygenase.