[20, 21] Secretion of IL-1A and IL-1B by keratinocytes was observed by Olaru et al. in an in vitro model of keratinocytes incubated with S. aureus.[20] Cheng et al. observed that infection with C. trachomatis leads to the secretion of IL-1A by keratinocytes [21]. Here, IL1B is linked to infection.