CHI3L1 and neoplasm: The results showed that the expression of some tumor-related genes, including CHI3L1, collagen 1A1 (COL1A1), and C-X-C motif chemokine ligand 14 (CXCL14), in PTC2 was significantly higher than that in PTC1, but the expression of some immune-related genes, such as IGH, IGKC, IFI6, and IFI27, in PTC2 was significantly lower than that in PTC1 (Fig. 4B).