Chemokines are a superfamily of small, secreted proteins that regulate cell traffic in homeostatic and inflammatory conditions. Keratinocytes synthesize many chemokines, including members of the CC and CXC subfamilies, such as regulated on activation of normal T-cell expressed and secreted, gamma-interferon inducible protein-10, monokine induced by gamma-interferon, and thymus- and activation-regulated chemokine. They also express some chemokine receptors that mediate the inflammatory or immune response by attracting various kinds of leukocytes.