Overexpression of CXCR4 in tumor buds is a strong predictor of lymphatic invasion and lymph node metastasis in colorectal cancer E. Karamitopoulou-Diamantis * , D. Kassahn, I. Zlobec, V. Koelzer, H. Dawson, A. Lugli * Universität Bern, Inst. für Pathologie, Switzerland