When 383 poorly differentiated CRC patients were compared to 1,831 moderately or well differentiated CRC patients, the result from ten studies demonstrated that no significant relationship was found between CD166 expression and tumor differentiation (OR = 1.45, 95% CI = 0.80-2.63, P = 0.217) (Figure 6). The gene discussed is ALCAM; the disease is colorectal carcinoma.