Recently, Pier Paolo Pandolfi and colleagues found miR-22 promotes the EMT, tumor invasion and metastasis of normal and cancer mammary stem cells by targeting TET1, TET2 and TET3; miR-22 overexpression enhances some stemness and EMT-related genes expression, such as BMI1, ZEB1 and ZEB2. The gene discussed is BMI1; the disease is cancer.