Large-scale and high-throughput proteomics experiments of specific samples provide substantial amounts of identified proteins and peptides, which increasingly find their way into centralized, public data repositories. These data typically have potential beyond the analyses performed by the original authors, and can therefore provide considerable added value by being reused for specific, unexplored enquiries. We here reanalyze two CNS-related proteomics datasets, one from the HUPO's Brain Proteome Project, and one from a comprehensive analysis of cerebrospinal fluid in light of the expression of specific splice isoforms from CNS-related genes. We also evaluate the empirically observed peptides of interest against predictions of their proteotypic character.