CD4 and Cowden disease: Coeliac disease (CD) is an immune-mediated malabsorption syndrome occurring in genetically susceptible individuals intolerant to dietary gluten.1 The pathogenesis of CD involves the generation of effector innate and adaptive immune responses.1 The latter involves activation of gliadin-specific CD4+ TCRαβ T cells within regional lymphoid tissue, with trafficking of effector memory gliadin responsive CD4+ T cells to the lamina propria (LP), and concomitant stimulation of humoral immune responses directed towards tissue transglutaminase type 2 and deamidated gliadin.