Ganghammer S, Gutjahr J, Hutterer E, Krenn PW, Pucher S, Zelle-Rieser C, Jöhrer K, Wijtmans M, Leurs R, Smit MJ, Gattei V, Greil R, Hartmann TN. Combined CXCR3/CXCR4 measurements are of high prognostic value in chronic lymphocytic leukemia due to negative co-operativity of the receptors. Haematologica 2016; 101(3):e99-e102; https://doi.org/10.3324/haematol.2015.133470.