Content: Introduction to biomarker discovery and validation; Clinical context of proteomics biomarker discovery and validation, authority regulations; Biomarker discovery: Patient selection; Biomarker discovery: Experimental design and biobanking; Biomarker discovery: body fluids; Biomarker discovery: tissues; Biomarker discovery: mass spectrometry based profiling platforms; Biomarker discovery: array based profiling platforms; Biomarker discovery: data preprocessing for LC-MS data; Biomarker discovery: data preprocessing for Maldi imaging, and 2D electrophoresis and protein arrays data; Biomarker discovery: statistical analysis and validation; Biomarker validation: biomarker validation methods; Functional biomarker validation; Clinical application: case studies Clinical application: summary and future technology development trends