Reversible and permanent effects of tobacco smoke exposure on airway epithelial gene expression

Table 4 Biomarker of tobacco smoke exposure constructed using the 28 irreversible genes

	Training set			Test set	GSE4115			GSE5372
	Never	Former	All	Current	Former	Current	All	Non-smokers	Smokers	All
Number Classified Correctly	21	31	52	46	38	38	76	4	4	8
Total Number	21	31	52	52	47	38	85	4	5	9
Accuracy	100.0%	100.0%	100.0%	88.5%	80.9%	100.0%	89.4%	100.0%	80.0%	88.9%
Mean of Random sets			52.5%	59.2%			59.2%			50.1%
P value			0	0.102			0.013			0.001

The accuracy of the biomarker is reported for the training set samples, test set samples, samples from dataset GSE4115 that do not overlap with the present study, and samples from GSE5372. The P values represent the proportion of 1,000 random training sets that have the same or better accuracy on the tested samples as the actual biomarker.

ISSN: 1474-760X