High-throughput immunoblotting or Western array screening of tissue is a unique advancement in proteomics that may help researchers in their quest to elucidate the proteins and signaling pathways involved in complex human pathologies such as atherosclerosis. The technique entails polyacrylamide gel electrophoresis and Western blotting followed by screening of the blots with hundreds of high-quality antibodies that are combined into unique cocktails. Because each monoclonal antibody identifies a unique target among the array of thousands of proteins displayed on the Western blot, subnanogram quantities of proteins with altered expression can be readily detected. This approach of proteome analysis avoids the limitations of traditional high-throughput protein screening techniques such as two-dimensional gel electrophoresis and mass spectrometry.