CD44 and colorectal carcinoma: However, when we used CD68 to stain and quantify the macrophages in CRC tumor samples, CRCs with CSF1R c.1085 genotype A_G did not contain higher number of macrophages than those with CSF1R genotype A_A [8], suggesting CD44 expression levels did not show a positive correlation with the number of macrophages in tumor tissue.