Thus, MEKK1 null mutants showed reduced levels of 1K1N cells compared to parental T. brucei EATRO 1125 AnTat1.1 90:13 cells (Fig 8B centre ‘MEKK1KO’), whereas the induction of TbTOR4 RNAi in the MEKK1 null mutant resulted in significantly more 1K1N cells on day 3 and day 4 of infection with respect to when TbTOR4 RNAi was not induced (Fig 8B right). The gene discussed is MAP3K1; the disease is infection.