CXCL16 and neoplasm: However, while the expression of Cxcl16 mRNA is similar in between glyCAF, apCAF, and myeloid cells, post-transcriptional regulations of the RNA are differentially occurring in these cells, with the highest protein expression observed in the glyCAF (Fig. 5f), suggesting that glyCAF are the primary source of CXCL16 at the tumor margin.