VNN1 and brain cancer: The remaining five out of 11 dolphin serum proteins, which were not observed in the initial human and pig serum proteome analysis and had a differential rank greater than 200 compared to the reference human proteome, were: Adiponectin, Vanin-1, Polymeric immunoglobulin receptor, Adipocyte plasma membrane protein, and Deleted in malignant brain tumors 1.