ERG plays a nonredundant role in proliferating T-ALL cells. (A) ERG knockdown (kd) in MOLT4 cells. A Western blot of nuclear lysates from MOLT4 clones transduced with retroviral vectors encoding either control shRNA (kd CON) or shRNA targeting ERG (kd ERG) vectors showing reduced ERG protein in the latter relative to DNA topoisomerase 1 control. (B) Morphology; cytospins of MOLT4 cells transduced with either the control vector (kd CON) or knockdown vector (kd ERG) stained with Wright stain. (C) Cell-cycle kinetics and viability: kd ERG MOLT4 cells show increased apoptosis and impaired progression through the cell cycle. These data are representative of duplicate experiments each recording 105 events. (D) Comparative growth curves: MOLT4 cells stably transduced with an ERG knockdown vector show a significant reduction in growth rate compared with those transduced with a control vector. The data show replicates of 3 separate experiments each using a starting number of 105 control and ERG knockdown cells.