IL1B and infection: The availability of preformed IL-1α (but not IL-1β) protein in steady-state (Fig 6D, S6 Fig), which can be rapidly released in response to stimulation, together with the strategic position of keratinocytes as the first contact point between the host and the infecting fungus, suggested that keratinocyte-derived IL-1α likely functions as an ‘alarmin’ right at the onset of infection to alert the host about fungal invasion and to initiate a protective antifungal response.