To explore whether miR-10a can suppress hoxd4 expression, the expression levels of the hoxd4 and hoxb4 mRNAs were compared to those of miR-10a and -10b in several human cell lines including human breast cancer cells MDA-MB-231 and MCF7, human mammary epithelial cells (MCF10A), hepatocellular liver carcinoma cells (HepG2), cervical carcinoma cells (HeLa) and lung adenocarcinoma cells (A549) (Fig. 1c, d). Here, HOXD4 is linked to lung adenocarcinoma.