Table 3. p16 protein expression according to genetic alterations observed in the p16 gene^*.

Genetic and epigenetic alterations to the p16 gene	p16 Expression
	Positive†	Negative†
None	6‡	1§
One hit
Hemizygous deletion	2‡	2§
Promoter methylation	3‡	0§
Two hits
Homozygous deletion	0‡	1‡
Hemizygous loss plus promoter methylation	1§	3‡
Hemizygous loss plus mutation	0‡	1‡
Total	12	8

^*Twenty tumors were analyzed for p16 expression using immunohistochemistry. Images of tumors 4, 13, 31, and 34 are provided in Figure 6, B.

^†Positive and negative scoring as described in the text.

^‡Concordant results between protein expression and genetic/epigenetic alterations (n = 16).

^§Discordant results between protein expression and genetic/epigenetic alterations (n = 4).