Table 3. Association between allelic variation^a and CYP1A1 protein expression in pterygium (n=150) and control^b (n=50) subjects.

	CYP1A1 protein expression, n (%)
Genotype	Negative	Positive	p
Pterygium			0.027
m1/m1	40 (39.2)	10 (20.8)
m1/m2 and m2/m2	62 (60.8)	38 (79.2)
Control			1.000
m1/m1	25 (52.1)	1 (50.0)
m1/m2 and m2/m2	23 (47.9)	1 (50.0)

^aCYP1A1 allelic variants analyzed in this study are based on prior pterygium samples [14,15]. ^bFrom superior conjunctiva of 20 patients and medial conjunctiva of 30 patients without pterygium or pinguecula. The CIP 1A1 protein in pterygium and conjunctiva controls was detected by immunohistochemistry.