Abstract: A system (100) for classifying a biological test sample, including a database (112) populated with reference expression data. The reference expression data includes expression levels of a plurality of molecules (polynucleotides or polypeptides), including a set of marker molecules, in a plurality of reference samples. Each reference sample has a pre-assigned value for each of one or more clinically significant variables. The system includes at least one processor (110) and at least one storage medium containing program instructions for execution by said processor (110). The program instructions cause the processor to accept (122) input expression data including a test vector of expression levels of the marker molecules in the biological test sample; and pass the input expression data to one or more analysis programs (130a, 130b, 35).