PDCD1 and hepatitis C virus infection: Additional phenotypic profiling demonstrated that PD-1+Tim-3+CD8+ T cells expressed greater levels of activation and memory markers than did PD-1−Tim-3−CD8+ T cells, similar to the pattern observed during hepatitis C virus infection.16 Our study indicates that PD-1 and Tim-3 co-expression represents a TInt phenotypic signature, and that these molecules may favor the survival and maintenance of this special CD8+ T-cell subset at the maternal–fetal interface.