TP53 and head and neck squamous cell carcinoma: In summary, in this HNSCC GWAS, which includes diverse populations, we identify 18 novel genome-wide associated variants and 11 HLA-specific novel variants associated with HNSCC and its subsites, including rs78378222 in the TP53 3′ UTR, which confers a 40% reduction in odds of developing overall HNSCC.