The levels of CD3, CD4, CD8, CD68, and CD206 expression in pancreatic cancer were found to be independently correlated with tumor recurrence by immunohistochemistry.26 In addition, during clinical management, chemotherapy was found to be associated with long‐term changes in different phenotypes of circulating lymphocyte levels.11, 27 In this study, we demonstrated that the low level of CD8+ naïve/memory ratio after the third cycle of first‐line chemotherapy was correlated with improved clinical response (SD vs PD: 0.87 ± 0.13 vs 2.76 ± 0.69, P = 0.01). Here, CD8A is linked to neoplasm.