1. A method of assigning a sample to a known or putative class, comprising the steps of: a) determining a weighted vote for one of the classes for one or more informative genes in said sample in accordance with a model built with a weighted voting scheme, wherein the magnitude of each vote depends on the expression level of the gene in said sample and on the degree of correlation of the gene's expression with class distinction; and b) summing the votes to determine the winning class and a prediction strength, wherein said sample is assigned to the winning class if the prediction strength is greater than a prediction strength threshold.