TGM2 and cranioectodermal dysplasia: Still, they could not entirely rule out the influence of other pathogenic factors or a natural fluctuation in CeD incidence.100 However, a prospective German study found that adult patients exposed to mild COVID-19 infection had persistent higher levels of CD-specific anti-tissue transglutaminase antibodies (compared to uninfected blood donors), also months after the infectious period, perhaps indicating a future rise in CeD incidence.101