Detection of more than 101 HER2+EVs per μl of plasma and mean fluorescence intensity for HER2 surface expression ≥ 1.5 × 103, which is above two standard deviations of the HER2 expression of HER2+EVs isolated from healthy individuals, characterised breast cancer patients with a high probability of having an HER2pos tumor. This evidence concerns the gene ERBB2 and breast carcinoma.