Compared to that in healthy individuals, the serum TACSTD2 level was significantly increased in patients with cervical cancer, colon cancer, esophageal carcinoma, glioma, liver cancer, lung cancer, pancreatic cancer, prostate cancer and thyroid carcinoma, while the traditional tumor marker CEA was only differentially elevated in the serum of patients with colon cancer and rectal cancer (Fig. 4F and G). Here, TACSTD2 is linked to central nervous system cancer.