In patients with BMI ≥ 25 kg/m2, the presence of B-CLS > 1 in HER2 + ER− breast tumours was associated with shorter time to metastatic disease (p = 0.031) (Supplementary Fig. 1e) whereas there was a trend for a possible association in the HER2 + ER + patients (p = 0.097) (Supplementary Fig. 1f). This evidence concerns the gene ERBB2 and metastatic neoplasm.