CD4 and colorectal carcinoma: According to the area under the receiver operating characteristic curve (AUC), the absolute value of CD4+ TSCM used to assist in the diagnosis of CRC was 0.758 (sensitivity: 0.612; specificity: 0.788), which is higher than the values for CEA (AUC: 0.707) and CA199 (AUC: 0.552).