IL1A and inflammatory skin disease: Even though decreased icIL-1Ra1 expression has been detected in lesional psoriatic skin compared to uninvolved psoriatic or normal skin (98, 99), an increased ratio of icIL-1Ra1 to IL-1α, mainly due to the reduction of IL-1α, has been reported in human inflammatory skin diseases, including psoriasis or AD (99, 112, 113).