Keywords Betacells.Enterovirus.Enterovirusdetection.Enterovirusinfection.Type1diabetes.Vp1immunostainingThe pathogenesis of type 1 diabetes is widely believed toinvolve T cell-mediated autoimmune processes directedagainst the insulin-producing beta cells in the pancreas.Growing evidence suggests that environmental factors,including toxins, food antigens and, particularly, viralinfections are involved in the induction of type 1 diabetes.Viruses such as enteroviruses, rubella virus, mumps virus,rotavirus, parvovirus and cytomegalovirus have beeninvestigated in experimental and clinical studies aimed atdefining their roles in the pathogenesis of type 1 diabetes.Most efforts in recent years have focused on enteroviruses,the most common cause of viral infection in humans,infecting an estimated billion people annually worldwide[1]. Enteroviruses exhibit islet cell tropism, as demonstratedby the detection of viral RNA by in situ hybridisation andthe identification of viral proteins by immunohistochemicalstaining of post-mortem pancreatic specimens from type 1diabetogenic patients [2, 3]. Furthermore, an infectiouscoxsackievirus B4 was isolated from the islets of a type 1diabetic patient [2], and a strain of echovirus 3 was isolatedfrom an individual concurrently with appearance of isletcell and IA-2 autoantibodies [4].The study by Richardson and collaborators [5], pub-lished in this issue of Diabetologia, is a welcome additionto the field, supporting the relevance of enteroviruses asdiabetes-inducing agents. The authors have studied highlyvaluable human material—the autopsy pancreases ofrecent-onset diabetic patients—for the presence of entero-viruses. Enteroviral antigen-positive islet cells were foundin 44 of 72 young recent-onset type 1 diabetic patients, inline with the original findings of other groups [2, 3].Furthermore, islets from ten of 25 cases with type 2diabetes tested positive for the enteroviral capsid proteinvp1 by immunohistochemistry [5], pointing to a possiblerole of these viruses in the aetiopathogenesis of this diseaseas well. As negative controls, they investigated 50 pan-creases from neonatal or paediatric non-diabetic individuals,reporting three vp1-positive samples. In the studied isletpreparations, vp1 staining was restricted to beta cells andcorrelated well with the immunostaining of double-strandedRNA-activated protein kinase R. With the help of thisenzyme, the authors aimed to confirm that the vp1-positiveinsulin-containing cells represented virus-infected cells.Human enteroviruses comprise a large group of patho-gens that are subdivided into four species—A, B, C and D—with more than 100 different serotypes. All the enterovirusserotypes investigated to date, in prospective studies, isletcell culture or animal studies, appear to include strains withthe ability to damage beta cells. In contrast to previousstudies that used serotype-specific methods, recent progressin the field of enterovirus-associated type 1 diabetes has, toa large extent, involved the application of enterovirusgroup-specific verification procedures. There is an antibodyon the market (clone 5D8/1; Dako, Glostrup, Denmark) that