Thymic stromal lymphopoietin

Thymic stromal lymphopoietin (TSLP) is an interleukin (IL)-7-like cytokine, alarmin, and growth factor involved in numerous physiological and pathological processes, primarily those of the immune system. It shares a common ancestor with IL-7.

Source: Wikipedia — Thymic stromal lymphopoietin (CC BY-SA 4.0)