In addition, the levels of DC-associated cytokine CCL21 and B cell-associated cytokine CXCL12 were upregulated in the tumor diameter ≥3 cm group (Student’s t-test, CCL21, p = 0.0471; CXCL12, p = 0.0432), suggesting that as the primary colorectal cancer lesion grows, the tumor secretes more cytokines, such as CCL21 and CXCL12, into the peripheral blood to recruit APCs (Figure 6G). Here, PPIB is linked to colorectal cancer.