The observation that some proteins like Akr1b1, Lamp1, Tfrc, and Glu1 were found to increase their concentration at the pre-symptomatic stage of the disease but returned to baseline at the more advanced stage is intriguing but not fully understood at this time, owing to the many factors and cell types involved in tumor growth and the non-trivial link between the protein profile of circulating fluids and tumor stage. Here, AKR1B1 is linked to neoplasm.