The dichotomous roles of the IL-1 cytokine family members. Cytokines of the IL-1 family are involved in many processes during health and disease. Their role is, however, often dichotomous, with the balance between benefit and harm quite fragile. In many diseases, including infections, GVHD, MBI, and cancer, in general “too much” cytokine release seems harmful, emphasizing the “Goldilocks principle” which states that the immune response should be “just right.” HSC, hematopoietic stem cell.