ERBB2 and cancer: On the contrary, miR-let-214 and miR-15a were expressed in low HER2-expressing cancers, as well as the low Ki-67 group, while miR-27a, miR-92a, miR-301a, miR-355a, and miR-16 were abundant within low HER2-expressing tumours, yet overexpressed in cancers with high Ki-67 expression.