title: Blocking PD-1 in cancer immunotherapy.
abstract: The PD-1 pathway is emerging as an important tumor-evasion mechanism. In this issue of Blood, 3 independent groups report that PD-1 is highly expressed by tumor-specific cytotoxic T lymphocytes in hematologic and nonhematologic malignancies, and is associated with impaired T-cell function.
authors.affiliation: Baylor College of Medicine, USA.
authors.forename: Gianpietro
authors.initials: G
authors.lastname: Dotti