<h4>Background</h4>We investigated the hypothesis that transforming growth factor β induced (TGFBI), an extracellular matrix protein secreted in the microenvironment of several tumors, can act as a secreted immune checkpoint (sIC) that contributes to the suppression of human antitumor T cell responses.<h4>Methods and results</h4>Serum TGFBI concentrations, measured by ELISA, were significantly higher in patients with colorectal cancer (CRC) and hepatocellular carcinoma than in healthy individuals and associated with poor overall survival. The gene discussed is TGFBI; the disease is colorectal cancer.