In the past decade or so, Th17 cells, have emerged as key players in autoimmune disease, as well as certain cancers and allergies. These potentially dangerous cells are normally regulated by endogenous mechanisms that include Treg cells, which serve to prevent autoimmunity. However in people who develop autoimmune disease, the regulation of Th17 cells goes awry, resulting in inappropriate and damaging inflammation. Dr Fletcher’s research career has focussed on understanding the role and regulation of Th17 cells in human diseases including MS, RA, psoriasis, cancer and hidradenitis suppurativa (HS), which is a debilitating yet under recognised skin disease. Importantly, studying the role of these cells in different diseases allows for greater understanding of common underlying mechanisms that can be translated to benefit for patients. The overarching research aim is to understand the role of Th17 cells in human disease and how they can be targeted to develop new or improved therapies.