Corrigendum to "Externally validated HPV-based prognostic nomogram for oropharyngeal carcinoma patients yields more accurate predictions than TNM staging" [Radiother Oncol 113 (2014) 324–30]. Issue 2 (August 2017) - Velazquez, Emmanuel Rios; Hoebers, Frank; Aerts, Hugo J.W.L.; Rietbergen, Michelle M.; Brakenhoff, Ruud H.; Leemans, René C.; Speel, Ernst-Jan; Straetmans, Jos; Kremer, Bernd; Lambin, Philippe