Table 1.

Genomic alterations of SMAD4 in tumors obtained from HNSCC patients in TCGA. Samples are called SMAD4 low when their log transformed RSEM expression for SMAD4 from RNA-sequencing data is below the maximum value of SMAD4 expression for homozygous deletions or nonsense mutations

HPV	SMAD4	SMAD4.Low	SMAD4.High
HPV+	Homozygous Deletion	0	0
	Nonsense Mutation	0	0
	Missense / Silent Mutation	0	1 (p.P298S)
	WT	3	32
HPV-	Homozygous Deletion	13	0
	Nonsense Mutation	2 (p.S242*; p.Q461*)	0
	Missense / Silent Mutation	2 (p.W99C; p.R361H)	2 (p.P544L; p.K46K)
	WT	122	102