CTLA4 and thyroiditis: In hepatocellular carcinoma, follicular lymphoma, thyroid and high-grade serous ovarian cancer, PD-1 is upregulated on CXCR5+CD8 T cells while TIM3 and CTLA4 are downregulated compared to CXCR5−CD8 T cells possibly indicating a Tpex versus Tex phenotype (15, 21, 24, 25).