MKI67 and cancer: Although CCK8 revealed 4T1/miR-204 KO had no influence on cancer cells proliferation (Supplementary Fig. 5a), the tumour volumes, tumour weight and Ki67 positive cells from mice xenografted with 4T1 tumours were much larger than 4T1/miR-204 KO tumours in vivo (Supplementary Fig. 5b, c, d).