Abstract: Protein biomarkers that may advantageously be utilized in diagnosing prostate cancer, benign prostate hyperplasia or to make a negative diagnosis are described. Accordingly, in one aspect of the invention, methods for aiding in, or otherwise making, a diagnosis of prostate cancer or benign prostate hyperplasia are provided. In one form of the invention, a method includes detecting various protein biomarkers of defined molecular weight and correlating the detection to a diagnosis of prostate cancer, benign prostate hyperplasia or to a negative diagnosis. In yet another aspect of the invention, kits are provided that may be utilized to detect the biomarkers described herein. In a further of the invention, methods of using a plurality of classifiers to make a probable diagnosis of prostate cancer of benign prostate hyperplasia are provided. In certain forms of the invention, the methods include use of a boosted decision tree analysis. Various computer readable media are also provided.