Table A1.

(A) Confusion matrix. (B) Example of confusion matrix.

(A) Confusion matrix
		Pulmonary Toxicity
		High	Low
Gene expression level (fold of control)	≧Cut off value	a (True positives)	b (False positives)
	<Cut off value	c (False negatives)	d (True negatives)
		a + c	b + d
Sensitivity = $\frac{\mathrm{The}\mathrm{number}\mathrm{of}\mathrm{true}\mathrm{positives}}{\mathrm{The}\mathrm{number}\mathrm{of}\mathrm{true}\mathrm{positives}+\mathrm{The}\mathrm{number}\mathrm{of}\mathrm{false}\mathrm{negatives}}$ = $\frac{a}{a+c}$ Specificity = $\frac{\mathrm{The}\mathrm{number}\mathrm{of}\mathrm{true}\mathrm{negatives}}{\mathrm{The}\mathrm{number}\mathrm{of}\mathrm{false}\mathrm{positives}+\mathrm{The}\mathrm{number}\mathrm{of}\mathrm{true}\mathrm{negatives}}$ = $\frac{d}{b+d}$ False positive = $\frac{\mathrm{The}\mathrm{number}\mathrm{of}\mathrm{false}\mathrm{positives}}{\mathrm{The}\mathrm{number}\mathrm{of}\mathrm{false}\mathrm{positives}+\mathrm{The}\mathrm{number}\mathrm{of}\mathrm{true}\mathrm{negatives}}$ = $\frac{b}{b+d}$ False negative = $\frac{\mathrm{The}\mathrm{number}\mathrm{of}\mathrm{false}\mathrm{negatives}}{\mathrm{The}\mathrm{number}\mathrm{of}\mathrm{true}\mathrm{positives}+\mathrm{The}\mathrm{number}\mathrm{of}\mathrm{false}\mathrm{negatives}}$ = $\frac{c}{a+c}$ a: The number of true positives, b: The number of false positives. c: The number of false negatives, d: The number of true negatives.
(B) Example of confusion matrix.
	CXCL5 at 1 week	Pulmonary Toxicity
		High	Low
Gene expression level (fold of control)	≧Cut off value	19	0
	<Cut off value	1	20
		20	20
For example, in CXCL5 at 1 week after instillation. Sensitivity = $\frac{19}{19 + 1}$ = 0.95, Specificity = $\frac{20}{0 + 20}$ = 1.00, False positive = $\frac{0}{0 + 20}$ = 0.00, False negative = $\frac{1}{19 + 1}$ = 0.05.