ERBB2 and breast cancer: From a clinical perspective, the concentration of biomarker‐positive EV, for example, vascular endothelial cadherin‐positive EVs, in 25 patients bearing colorectal cancer are in a range from 5.0 × 108/mL to 9.0 × 108/mL (Bar‐Sela et al., 2020); whilst EV concentrations of healthy subjects or patients with HER2+ breast cancer are around 3 × 108/mL and 10 × 108/mL, respectively (Liu et al., 2019).