When we compared cancer cases classified on the basis of surrogate molecular classification (Luminal A, Luminal B, HER2-amplified and Triple Negative), the Triple Negative subgroup showed the highest level of miR-210 expression (median 18.31 IQR 7.2–38.61), followed by Luminal B tumours (median 10.57 IQR 5.01–19.41), whereas Luminal A (median 8.6; IQR 4.2–15.09), and HER2-amplified tumours (median 8.57 IQR 4.66–24.69) showed the lowest expression levels (P = 0.0137). This evidence concerns the gene ERBB2 and cancer.