IAN-JAMES MALM ET AL: 'Expression profile and in vitro blockade of programmed death-1 in human papillomavirus-negative head and neck squamous cell carcinoma', HEAD & NECK, 9 April 2014 (2014-04-09), pages n/a - n/a, XP055202165, ISSN: 1043-3074, DOI: 10.1002/hed.23706