Moreover, we discovered that CRC patients with high TIMP1 expression expressed more immune checkpoint molecules than those with low TIMP1 expression (Supplementary Figure 8C, 8D), which was consistent with the “immunity tidal model theory” that high expression of both costimulatory and coinhibitory immune checkpoints caused an immunosuppressive phenotype in tumors [16]. Here, TIMP1 is linked to colorectal carcinoma.