Interleukin-22（IL-22） is a member of the IL10 family of cytokines that mediate cellular inflammatory responses and functions in antimicrobial defense at mucosal surfaces and in tissue repair. This protein also has pro-inflammatory properties and plays a role in in the pathogenesis of several intestinal diseases. IL-22 has a role in the remodeling of the uterine tissue in the inflammatory environment by regulating epithelial-mesenchymal transition markers called E- and N-cadherin. Therefore, IL-22 contributes to the proper regeneration of endometrial layers after inflammation-triggered abortion. Thus, it might have a practical significance to be utilized as a treatment option postpartum （enhanced regeneration function） and in secondary infertility caused by inflammation （enhanced barrier/protector function）. IL-22 is a crucial cytokine that regulates host immunity in infectious diseases, including COVID-19 （disease caused by SARS-CoV-2）.