In the past, JET results have been prominent in defining ITER. Only absolute performances matter in a reactor, and these have to be already optimised, JET can still increase the fusion power and energy produced. The main difficulty toward a reactor is the low performance of the divertor. An hybrid fusion-fission reactor could be an intermediate solution as the fusion power demand is reduced by a factor 10. In this respect, ITER is sufficient to be the core of such an hybrid reactor.