To predict and validate the interactions of YKL-40 in the tumor microenvironment, we analyzed mRNA expression of YKL-40, IL-17A, PD-L1, and MMP-8 in 136 samples of CRC tissue and non-cancerous colonic tissue obtained from Gene Expression Omnibus (GEO) datasets GDS4382, GDS4513, and GDS4515. The gene discussed is CHI3L1; the disease is neoplasm.