This Technical Specification gives recommendations for the handling, documentation and processing of FFPE tissue specimens intended for the analysis of extracted proteins during the preanalytical phase before a molecular assay is performed. This Technical Specification is applicable to molecular in vitro diagnostic examinations (e.g., in vitro diagnostic laboratories, laboratory customers, developers and manufacturers of in vitro diagnostics, institutions and commercial organizations performing biomedical research, biobanks, and regulatory authorities). Protein profiles and protein-protein interactions in tissues can change drastically before and after collection (due to e.g., gene induction, gene down regulation, protein degradation). Protein species amounts can change differently in tissues from different donors / patients. The expression of genes can be influenced by the given treatment or intervention (surgery, biopsy), or drugs administered for anaesthesia or even treatment of concomitant disease as well as by the different environment conditions after the tissue removal from the body. Furthermore, the formalin fixation and paraffin embedding process leads to modifications of the protein molecules, which can impact the validity and reliability of the analytical test results. Therefore, it is essential to take special measures to minimize the described profile changes and modifications within the tissue for subsequent protein analysis. This document is not applicable for protein analysis by immunohistochemistry.