These authors observed that the branch of the ACE2/Ang-(1–7)/MasR axis connected to the RAS is associated with anti-proliferative and anti-metastatic properties, and they further found that the ACE2 protein levels are negatively correlated with the metastatic ability of breast cancer cells and the grade of breast tumors and showed that the up-regulation of the ACE2/Ang-(1–7)/MasR axis could inhibit breast cancer cell metastasis in vivo and in vitro (Yu et al., 2016). Here, ACE2 is linked to breast neoplasm.