ENTPD1 and neoplasm: To evaluate the heterogeneity of tumor-specific T cells from CRC1 to CRC4 patients, we analyzed the frequency of CD39+CD103+, PD-1+CD8+ subset and CXCL13+CD8+ subset T cells in peripheral blood lymphocytes (PBLs) and matched tumor-infiltrating lymphocyte (TILs) fragments derived from CRC patients using flow cytometry.