BB and AMO-miR-21 suppress colony formation. Colony growth capacity was assessed by methylcellulose colony formation assays. (A) Images of representative colony formation. (B) After incubation for 1 week, RPMI-8266 cells treated with 75 μM BB or 0.5 μM AMO-miR-21 were observed under a light microscope and the number of colonies counted. Three independent experiments were carried out.