Since we showed that C19orf10 can promote the proliferation of human BC cell lines in vitro and in vivo, it might be difficult to distinguish that the outgrowth of BC cells with a higher C19orf10 expression level is due to enhanced potential of metastasis or due to proliferation advantage in vivo if a non-orthotopic approach of tumor inoculation such as intravenous (iv) injection is used. The gene discussed is MYDGF; the disease is breast cancer.