TMEM219, also known as insulin-like growth factor-binding protein 3 receptor (IGFBP-3R), is a protein that acts as a cell death receptor for IGFBP-3 in breast and prostate cancers.95 It has been identified as a binding partner for IL-13Rα2 in the formation of the CHI3L1-IL-13Rα2–TMEM219 complex.30 The affinity of IL-13 with IL-13Rα2 has been reported to increase in the presence of TMEM219, which does not bind to IL-13Rα2. Here, CHI3L1 is linked to Familial prostate cancer.