IGIM and TRR261 have organized the 4th Summer School "Microbes, Host and Infection" in Tübingen kindly supported by CMFI and DZIF. The Scientific Sessions and the Career Session were also live-streamed. Thanks to the speakers of all sessions, all the nice posters and congratulations to the winners of the poster prizes (Eunjin Kim, Paul Lubrano, Cruz Matos de Opitz and Andreas Vorbach) and the winner of the talk prize (Franziska Höhn).