CXCL12 and colorectal carcinoma: The specific downregulation of LT in FL B cells combined with upregulation of CXCL12 in FL-CAFs suggest a CRC-like origin of at least some FL stromal cells since dark zone CRCs, unlike FRCs and versatile cells, do not require LT and TNF-α to maintain CXCL12 expression and the network morphology [27].