Table 1.

Assumptions

1. Selection of genes:

A gene whose mRNA was differentially expressed will exhibit differential protein expression with 50% probability.

2. Optimization of antibodies:

We will have 75% success rate optimizing commercially available antibodies for immunohistochemical assays on formalin-fixed paraffin-embedded tissues.

3. Individual assay outcomes:

For a given gene and subject and mRNA expression level, probabilities of immunohistochemistry outcomes relative to the median expression level for that gene are:

IHC outcome	mRNA ≥125% of median	mRNA ≤75% of median	MRNA within 25% of median
0	0%	75%	0%
1+	5%	15%	25%
2+	5%	5%	50%
3+	15%	5%	25%
4+	75%	0%	0%

4. Comparability of subjects:

The subjects for whom there is mRNA expression data are comparable to the subjects for whom there will be immunohistochemistry data.

Boldfaced numbers are also assumptions and can be varied.