The Marie Sklodowska-Curie project CORVOS, for COmplement Regulation and Variations in Opportunistic infectionS, is funded as an Innovative Training Network (ITN) – European Joint Doctorate (EJD). To keep it simple, one can say that CORVOS is an European-wide doctoral programme. Its focus lies on education of young scientists in the field of complement in opportunistic infections. This interdisciplinary doctoral program is supported by 10 European universities, 2 research institutes, 3 biomedical companies and 3 hospitals.