Correlation between indicators of BLV disease progression and Tim-3 mRNA expression in BLV-infected cattle. (A) Positive correlations were observed between proviral load ( n = 23) and Tim-3 expression in CD4+ cells and CD8+ cells. (B) Correlation between the leukocyte number and Tim-3 expression in BLV-infected cattle. (C) Correlation between IL-10 expression and Tim-3 expression in CD4+ cells was also positive. Proviral load and IL-10 mRNA expression were determined using quantitative real-time PCR analysis. Correlation statistics were analyzed by the Spearman rank test.