GAPDH and colorectal carcinoma: Using this approach, we obtained AUROC values of 0.5815 for CD45 (Fig. 2B), as might correspond for an unspecific marker, while 0.8430 for GAPDH (Fig. 2E), and 0.8351 for VIL1 (Fig. 2H), further validating both genes as reliable markers for the detection of CTC in metastatic CRC patients.