To further investigate the glycan locus in lung cancer cells, we used liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) to determine certain sites of glycosylation for CTSV. Glycopeptides carrying N-glycans were identified for 2 N-glycosylation sites, which is consistent with a previous study (Figures 2B, C). This evidence concerns the gene CTSV and lung carcinoma.