GFAP and colorectal carcinoma: GFAP expression in enteric glia in CRC tumor tissue showed large variation between patients and was found in varying locations within the tumors, ie, within the tumor stroma (Figure 3E), within peritumoral pre-existent stroma (Figure 3F), within intratumoral stroma in proximity to the plexus (Figure 3G), and toward the edge of the tumor distant from the plexus (Figure 3H).