ERBB2 and breast cancer: Interestingly, the plasma level of hsa-miR-100-5p was elevated in the Luminal A subtype but not the Luminal B, HER2 and TNBC subtypes (Luminal A, p = 0.0078; Luminal B, p = 0.0507; HER2, p = 0.2359; TNBC, p = 0.0975), and the plasma levels of hsa-miR-191-5p and hsa-miR-342-3p were highly expressed in all three subtypes of BC patients (p < 0.05) (Figure 4D).