ACTA1 and Erythema: By observing the erythema area change curve, epidermis and dermis thickness, collagen density, expression levels of α-SMA, TNF-α, vimentin, and type I collagen of the groups of mice subjected to either the short-term or long-term LL-37 administration, it was found that lesions induced by short-term administration could essentially fully recover without further intervention.