IL1A and histiocytic sarcoma: Toll-like receptors (TLRs) and interleukin-1 receptors (IL-1Rs) mediating cellular activation by TLR agonists and IL-1 family cytokines1,2, respectively, have been implicated in multiple autoimmune diseases, including the skin diseases hidradenitis suppurativa (HS) and atopic dermatitis (AD)3–9.