Enrichment of tetra-antennary glycans extended with N-acetyllactosamine in tumor and adjacent normal tissue from case 2417. The four indicated N-linked glycans (1–4) were detected by NSI-MS/MS. In the profiles shown at the right of each glycan, the MS/MS spectra associated with the TIM scan for the indicated tissue were filtered to present the detected signal intensity of a signature tetrasaccharide fragment (Hex-HexNAc-Hex-HexNAc). The presence of this fragment indicates the detection of a glycan extended with at least two N-acetyllactosamine repeats at a scan time which predicts the m/z ratio for the parent ion. For reference, the scan time for specifc m/z values is indicated by arrows in each filtered profile. The shading and shapes for the glycan structures reflect standard nomenclature adopted by the Consortium for Functional Glycomics (CFG; GlcNAc, blue square; Gal, yellow circle, Man, green circle; Fuc, red triangle, NeuAc, pink diamond).