The Affinomics programme aims to leverage existing efforts in Europe to generate large-scale resources of validated protein-binding molecules (‘binders’) as affinity reagents for characterisation of the human proteome and to apply them in comprehensive structural and functional analyses of protein expression, interactions and complexes. Proteome targets will be focused on five categories of inter-related human proteins involved in signal transduction, cell regulation and cancer, namely protein kinases, SH2 domain-containing proteins, protein tyrosine phosphatases, proteins somatically mutated in cancers and candidate cancer biomarkers. Binders to about 1000 protein targets will be made over the course of the programme. A high throughput, coordinated production pipeline for antigens and binders will be established. Target antigens will be expressed in three forms, as folded full-length proteins or domains, as large peptide fragments (PrESTs) based on low homology to other human proteins and as small peptides, in some cases phosphorylated. Binder types to be generated include affinity-purified polyclonal antibodies, monoclonal antibodies, recombinant antibody fragments and non-immunoglobulin scaffolds. An important aspect will be the development of highly efficient ‘next generation’ recombinant selection methods, based on phage, cell and ribosome display, capable of producing high quality binders at greater throughput and lower cost than hitherto. Systems and procedures for thorough binder validation and quality control will be established. The affinity reagents will be applied in advanced innovative and sensitive technologies for specific detection of target proteins and interacting protein complexes in cells, tissues and fluids, for improved understanding of protein function and new classes of diagnostic assays.