As the expression and accumulation of ENPP1 were observed only in cells that showed downregulation of miR-27b and low proteasome activity (Figs 5 and 7), these results indicate that miR-27b and ENPP1 expression may be useful early diagnostic markers to predict the malignant potential of luminal-type breast cancers. This evidence concerns the gene ENPP1 and breast carcinoma.