Here we have further analysed the exome-capture RNA sequencing filtered through the Matrisome database in ER-positive patients (n = 9) and identified elevation in ADAM22 expression in breast cancer brain metastatic tumours (Fig. 1c, Additional file 4 Table S2), with significant gain of ADAM22 expression in ER-positive brain metastasis (n = 9 patients, p = 0.0117) (Fig. 1d). This evidence concerns the gene ADAM22 and breast cancer.