Table 1.

 Expression of carbonic anhydrase IX (Ca9) in gastric cancer, as shown by immunohistochemistry

Characteristic	Moderately differentiated intestinal-type (n = 21)	Poorly differentiated intestinal-type (n = 9)	Diffuse-type (n = 27)
Age (y) (mean (SD))	68.3 (10.0)	60.0 (11.2)	62.0 (11.0)
Sex (M/F)	15/6	7/2	15/12
IRS of cancer cells	1.67 (1.73)	2.05 (1.99)	1.96 (2.10)
IRS of foveolar epithelium	5.50 (0.84)	5.88 (0.33)	5.52 (0.98)
p Value*	<0.001	<0.001	<0.001

IRS, immunoreactivity score.

*p values refer to differences between the IRS of cancer cells and foveolar epithelium.