Chemokines are small proteins (8-12 kD polypeptides) secreted by the cells of innate and adaptive immunity that mediate many of the functions of these cells, including recruitment of other cells. They are classified into families: CC, CXC and CX3C. CXC chemoattract mainly on neutrophils and CC act mainly on monocytes, eosinophils and mast cells. Mast cells are important cells in the modulation of allergic and inflammatory diseases. Activation of mast cells with specific IgE antibody and antigens or other active compounds such as Substance P and corticotrophin releasing hormone causes transcription and translation of several different cytokines/chemokines such as tumor necrosis factor-alpha (TNF-alpha), macrophage inflammatory protein-1 (MIP-1) and GM-CSF, RANTES, MCP-1, CXCL8, along with other proinflammatory compounds, proteases (chymase and tryptase), histamine, leukotrienes and prostaglandin D2. Neutralization of chemokines may reduce inflammatory cell accumulation and may protect against allergy, toxic shock syndrome and inflammatory diseases.