IL1RL2 and obesity due to melanocortin 4 receptor deficiency: As newly characterized members of the IL-1 family of receptors and cytokines, IL-36/IL-36R has forged new discoveries in the immune pathways associated with psoriasis, arthritis, obesity, intestinal, and many other chronic diseases [22,23,24,25], making it an attractive target for immune-based processes involved in disorders such as fibrosis.