ERBB2 and cancer: Herein, the authors explored the sensing of general exosome biomarkers (CD9, CD63, and CD81), and cancer-related biomarkers (CD24, CD44, CD54, CD326, and CD340) which could be identified on exosomal surfaces derived from the three distinct breast cancer cell lines (MCF-7, MDA-MB-231, and SK-BR-3).