GCC2 and lung cancer: TUBA1C, GAPDH, KRT25, GCC2, and POTEKP were collectively identified in exosomes from five NSCLC cell lines, including A549 (with the KRAS mutation), H1299 (with the neuroblastoma RAS (NRAS) mutation), PC9 (with the EGFR mutation), H1650 (with the EGFR mutation), and H522 (with the TP53 mutation), but they were not identified in exosomes from human pulmonary alveolar epithelial cells (HPAEpiCs), thus indicating that the five proteins were lung cancer exosome-specific proteins [145].