On the other hand, as AMPs are largely produced by epidermal keratinocytes, it is presumed that AMPs in the stratum corneum constitutively play an important role in providing a chemical barrier against intruding pathogens and opportunistic infections by commensal bacteria, along with the physical barrier function composed of both the corneocytes and the intercellular membrane bilayers containing ceramides. Here, ADSL is linked to Opportunistic infection.