Table 1. SOX2 expression in normal and preneoplastic lung lesions.

Tissue type	N	Immunohistochemistry Expression
		Positive	Negative
Normal bronchial epithelia	52	52	0
Normal alveoli	52	0	52
Atypical adenomatous hyperplasia (AAH)	37	0	37
Alveolar bronchiolization	4	4	0
Squamous dysplasia and carcinoma in situ	32	31	1