CCR6 and post-transplant lymphoproliferative disease: We also examined CXCR3, CCR4, and CCR6 on CD8 T cells and identified CD8+ Th1-like cells (CXCR3+ CCR6- CCR4-) which were markedly increased in PTLD relative to healthy controls (43.1% vs. 25.7%, Padj < 0.01), with a corresponding decrease in CD8+ Th1/17-like cells, defined as CXCR3- CCR6+ and CCR4+ (3.9% vs. 13.4%, Padj < 0.01).