Fig. 4. CCL5⁺ CTCs are positively correlated with circulating Tregs and predicted postoperative relapse in HCC patients.

a Immune-evasion-related genes and cytokines differentially expressed by CTCs and primary tumors. b Multiplex immunofluorescence images displaying the expression of CCL5 in primary tumors and CTCs detected in peritumoral microvasculature. mVI, microvascular invasion. The scale bars represent 20 µm, 200 µm, and 5 µm, respectively. c Multiplex immunofluorescence images representative of spatial relationship between the CCL5⁺ CTCs and CCR5⁺/FoxP3⁺ Tregs detected in peritumoral microvasculature. The scale bars represent 200 µm and 10 μm, respectively. d Scatterplot showing a positive correlation between the number of CCL5⁺ CTCs and the abundance of CCR5⁺ Tregs (CD4⁺, CD25^high, and CD127^low) (upper) and total Tregs (lower) in CD4⁺ T cells from HCC peripheral blood (n = 27 patients). e Kaplan–Meier analysis showing increased probability of early recurrence (left) and decreased overall survival rate (right) in patients with Treg^high/CTC^high in peripheral blood vs the other groups. I: Treg^low/CCL5⁺ CTC^low, II: Treg^low/CCL5⁺ CTC^high, III: Treg^high/CCL5⁺ CTC^low, and IV: Treg^high/CCL5⁺ CTC^high. The number of patients at risk for each group is listed below the Kaplan–Meier curve. A two-tailed Student’s t test was employed (d). Log-rank testing are performed to estimate the prognostic significance (e).