Lymphotactin is a secreted protein which belongs to the intercrine gamma family. It is also a member of the XC chemokine family. XCL1 is found in spleen with highest level, lower in peripheral leukocytes and very low levels in lung, colon and small intestine. XCL1 plays a role in inflammatory and immunological responses, inducing leukocyte migration and activation. XCL1 induces chemotactic function by binding to a chemokine receptor called XCR1. XCL1 is closely related to another chemokine called XCL2.