CELA2B (chymotrypsin-like elastase 2B) is a serine-type endopeptidase with proteolytic activity, particularly acting upon elastin 1. As a pancreatic elastase isoform (~29 kDa), CELA2B is secreted into the gastrointestinal tract where it undergoes limited degradation, making it detectable in fecal samples 1. The protein exhibits serine-type endopeptidase activity and is involved in proteolysis and protein binding functions [GO annotations]. CELA2B appears to participate in multiple biological processes including insulin catabolic processes and regulation of platelet aggregation, operating in the extracellular region [GO annotations]. In disease contexts, CELA2B has been identified as a downregulated hub gene in pancreatic ductal adenocarcinoma (PDAC) tissue compared to normal pancreas, suggesting potential involvement in pancreatic pathology 2. Additionally, CELA2B was identified in evolutionary genomics studies of Mycobacterium tuberculosis, where a specific codon site showed evidence of directional selection influenced by HIV-1 coinfection, indicating indirect interaction with human proteins that interface with HIV proteins 3. Clinically, CELA2B is evaluated as a diagnostic marker for exocrine pancreatic insufficiency through fecal elastase measurement, though polyclonal antisera demonstrate specificity for CELA3 isoforms rather than CELA2B 1. Further investigation is needed to clarify CELA2B's specific pathophysiological role compared to other elastase isoforms.