In contrast, miR-20b was also shown to enhance breast cancer proliferation both in vitro and in vivo by inhibiting expression of the phosphatase and tensin homologue (PTEN) gene (Zhou et al., 2014), a well-known tumor suppressor gene involved in regulation of breast cancer cells (DeGraffenried et al., 2004). The gene discussed is PTEN; the disease is breast carcinoma.