However, partially knockdown of CEP55 in breast cancer cells using shRNAs (sh#2 or sh#8) showed no significant changes in the number of cells displaying cytokinesis failure although complete knockdown of CEP55 by growing cells continuously in presence of doxycycline over 30 days showed increased proportion of cells in G2/M phase with multinucleation concomitant with increased cell death (Fig EV2C), suggesting that multinucleated cells are not viable over a long period of time. This evidence concerns the gene CEP55 and breast cancer.