HN	Head and neck
SCC	Squamous cell carcinoma
HPV	Human papilloma virus
OCD	International Classification of Diseases for Oncology
IARC	International Agency for Research on Cancer
OD	Odds ratio
RR	Relative risk
SIR	Standardized incidence ratio
SMR	Mortality rate ratio
WHO	World Health Organization
CI	Confidence interval
HIV	Human immunodeficiency virus
OSCC	Oral cavity squamous cell carcinoma
GVHD	Graft-versus-host disease
ADH	Alcohol dehydrogenase
ALDH	Aldehyde dehydrogenase
PY	Pack years
HR	Hazard ratio
EBV	Epstein–Barr virus
BMI	Body mass index