As expected, we showed that Bub1 phosphorylation of Cdc20 using in vitro kinase assays, was substantially reduced in the absence of Bub1 and that Cdc20 phosphorylation was suppressed in KSHV positive BC-3 cells which suggests that Bub1 is essential for Cdc20 phosphorylation. The gene discussed is BUB1; the disease is breast cancer.