IDO-1 is an important enzyme that controls immune responses. Since 2014, professor Ursula Grohmann was the recipient of an European grant, whose aim is to develop innovative drugs targeting this enzyme, which is known to be overexpressed in human tumor. But during the research, IDO-1 was also discoverd to be a protein that evolved acquiring the new function of signalling into the cells: in certain conditions, it can reprogram genetically the cells to control immune response. This finding permitted to develop new drugs, which are able to either potentiate this signalling activity or rather inhibit it.