Each year approximately 256,000 children and adults around the world develop a form of leukemia, and 209,000 died from it. Recently, some studies have evaluated the relationship between the concentration of some cytokines and prognosis of acute lymphoblastic leukemia. XCL1 is a lymphotactin that belongs to a cytokine subfamily called C or γ with only one cysteine in the N-terminal residue. It has been found with significant expression of receptor mRNA XCL1 (XCR1) in T and B lymphocytes and related to hematological neoplasms. For these reasons, XCL1 could be a efficient marker of prognosis in patients with acute lymphoblastic leukemia.