Fig. 8: Acetate levels correlate with CD8⁺ T cells in breast cancer patients.

a Serum acetate levels in breast cancer patients with and without comorbid depression (n = 28 and n = 24, respectively). b Immunohistochemical staining of CD8⁺ T cells on breast cancer tissue samples obtained from patients with and without comorbid depression (n = 17 and n = 11, respectively). The scale bars in the images represent 50 µm and 20 µm, respectively. c Spearman correlation analysis between serum acetate levels and the count of tumor-infiltrating CD8⁺ T cells (n = 28). The correlation was accessed by Spearman’s rank correlation coefficient (R = 0.61). The regression line is green, and the shading indicates the 95% confidence interval. d The relationship among serum acetate levels, count of tumor-infiltrating CD8⁺ T cells, and the depression score of breast cancer patients. Each sample (n = 28) was represented by a dot, with the dot’s size indicating the CD8⁺ T cell count and its color representing the serum acetate levels. e Kaplan–Meier metastasis-free survival curves for breast cancer patients with and without comorbid depression (n = 28 and n = 24, respectively). Statistical significance was determined by unpaired two-tailed Student’s t-test. Significance levels are denoted as *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001. Source data and exact p values are provided in the Source data file.