Figure 4.

The misclassification rate for each animal of the test set in the study of cross-platform transferability of signature genes. The study of cross-platform transferability of signature genes involved 54 permutations (that is, two microarray platforms × three ACs × three CT sets × three algorithms), resulting total of 108 classifiers (that is, transfer from Affymetrix to Agilent and vice versa). The misclassification rate is calculated by dividing the frequency of misclassification for each animal by the total number of classifiers (that is, 108 classifiers) for the test set. Each bar is divided into two colors; the blue is associated with the misclassification for the classifiers selected by the cross-validation while the red is for the classifiers using the transferred signature genes. The label above the bar is the RHI score. All the misclassified animals had the RHI scores of 0, 1 or 2, and no animals with RHI=3 and 4 were misclassified. the samples (that is, animals) misclassified by the cross-validation driven classifiers in one platform likely occurred in another platform using the transferred signature genes, indicating the performance of the classifiers was not affected by the choice of the signature genes as long as they were validated in any platform. Animals 27, 39, 45, 43 and 83 were misclassified by all the classifiers.