Professor David Jackson tells us about the role of the lymphatic system in immunity and cancer. The lymphatic system is a network of vessels collecting the fluids leaked from the blood vasculature. Its filtering function makes it an ideal compartment for the immune system. It is also a pipeline for metastasizing tumour cells to spread to distant tissues. Professor David Jackson studies how leukocytes and tumour cells enter the lymphatic vessels from the surrounding tissues. Professor Jackson's research has the potential to help us better control the spread of tumours, block unwanted immune responses in autoimmune diseases, block tissue rejection and make vaccines more effective. Creative Commons Attribution-Non-Commercial-Share Alike 2.0 UK: England & Wales; http://creativecommons.org/licenses/by-nc-sa/2.0/uk/