Fig. 1.

NKA expression in the perioperative period based on stage and risk factors. (A) NKA was downregulated after surgery on POD3 and recovered on POD30. The NK VUE ELISA assay was used to measure NKA levels in the peripheral blood of patients with CRC. (B) NKA was upregulated at the recovery stage (POD30) when compared to baseline in patients with stage III/IV CRC. (C) NKA was significantly upregulated on POD30 in patients with high-risk factors. (Data were statistically analyzed using the two-tailed Mann–Whitney U test and two-tailed Wilcoxon matched-pairs signed-rank test and are presented as a scatter plot with the median. *P < 0.05, **P < 0.01, ***P < 0.001); NKA: natural killer cell activity; CRC: colorectal cancer.