Follicular dendritic cells (FDC; CD45−CD31−Pdpn±) and recently defined Cxcl12-expressing reticular cells (CRC; CD45−CD31−Pdpn±) (11) secrete B cell chemoattractants CXCL13 and CXCL12, respectively. This evidence concerns the gene CXCL12 and colorectal carcinoma.