For example, miR-191-5p regulates cortical development by targeting brain-derived neurotrophic (factor BDNF) (Mellios et al., 2008), and promotes the proliferation and migration of human breast cancer cells by targeting special AT-rich sequence-binding protein-1 (SATB1) (Nagpal et al., 2013). The gene discussed is BDNF; the disease is breast carcinoma.