Did you know there is a relation between the microbiome and brain cancer? Or that the flu vaccine seems to decrease the chance of heart attacks? These connections might seem totally unrelated, but nothing is unrelated regarding the immune system. That is why this year’s Infection and Immunity Symposium will revolve around the theme: “The missing link; uncovering the invisible connections”. This theme aims to explore the often overlooked, and therefore missing, connections between diseases or symptoms in the field of Infection and Immunity. With this theme we would like the young researchers to think outside of the box and colour outside of the lines.