The molecule interleukin-7 (IL-7) is an important regulator of the development and signalling function of T cells, the white blood cells involved in fighting off infection and coordinating an efficient immune response. Loss of IL-7 signalling in humans results in a complete lack of T cells, demonstrating the necessity of IL-7 in the development of these important cells. After T cells mature, they circulate through the blood, searching out invading pathogens, mounting an immune response and clearing the infection. This process generates specialized memory T cells, which are able to mount a stronger and more efficient immune response upon subsequent encounters with the same pathogen. Memory cell development is the basis of vaccination, which serves to “prime” the immune system to ward off infections. Growing evidence indicates that not only is IL-7 essential in the development of these memory T cells, but that its overproduction is also implicated in a number of immune system cancers. Lisa Osborne was previously funded by MSFHR for her early PhD research training. She is now continuing her studies of IL-7. Using a number of genetic models of IL-7 signalling, Osborne will clarify the IL-7 mediated biochemical pathways that are involved in a number of T cell processes. She aims to demonstrate which molecule or pathway is primarily involved in the de-regulated growth of T cells that leads to cancer. Ultimately, this research could guide the development of vaccines that rely on the generation of memory T cells against a particular pathogen. Her work will also provide insights into the development of immune system cancers, and potentially a novel treatment approach.