CXCR4 and acute lymphoblastic leukemia: The prognostic significance of CXCR4 and VLA‐4 expression was evaluated in 29 adult and 25 paediatric patients with ALL,106 and only in adult patients, high CXCR4 expression was associated with shorter disease‐free survival (DFS) and OS and low VLA‐4 expression associated with shorter DFS.106