Analyses of mitotic progression and the completion of cell division using RNAi screening, biochemistry and imaging. CLICK HERE FOR A HIGH RESOLUTION IMAGE. A. High-throughput, high-content RNAi screening identifies UBE2S as a regulator of mitotic exit after taxol-induced mitotic arrest. B. The function of UBE2S as an ‘E4’ cofactor for the APC/C E3 ligase is revealed by biochemistry C. A two-step model for human APC/C function in substrate degradation leading to mitotic exit (see Garnett et al Nature Cell Biol (2009)). D. A role for Orc6 in cytokinesis revealed by combining a temperature sensitive degron-Orc6 with fluorescence photobleaching (see Bernal & Venkitaraman J Cell Biol(2011)).