Neopterin is a marker for cell immunity activation and can induce many inflammatory mediators, which reported to participate in AE progression. CHI3L1 is mainly expressed in microglia during inflammation, which participate in AE pathogenesis. OPN can induce B cell proliferation and antibody production, it is also crucial in Th17 cell differentiation, hence contributing to the development of AE. Here, CHI3L1 is linked to acrodermatitis enteropathica.