So that is one way. As for Tregs, ''In mice and humans, CCR8+ Tregs constituted 30 to 80% of tumor Tregs in various cancers and less than 10% of Tregs in other tissues, whereas most tumor-infiltrating conventional T cells (Tconvs) were CCR8–. CCR8+ tumor Tregs were highly differentiated and functionally stable.'' https://www.pnas.org/doi/10.1073/pnas.2114282119