ENO2 and lung carcinoma: This research focuses on NSEγ, a 47.2kDa, 434 amino acid long protein, due to specificity for neurons andneuroendocrine cells (UniProt accession number P09104).31 With this top-down LC-MS method, we quantifiedthe acetylated form of NSEγ, likely a PTM, which we describedin previous work.33 Normally, serum NSEconcentrations are in the low nanogram per milliliter (nM) range.Elevated concentrations of NSE are linked to lung cancer with a cutoffvalue of ≥25 ng/mL.32