CHI3L1 and posterior cortical atrophy: Recently, it has been shown that CHI3L1 binds interleukin 13 receptor alpha‐2 (IL‐13Rα2) and that CHI3L1, IL‐13Rα2, and IL‐13 form a multimeric complex.11 To explore the role of CHI3L1 in PCa metastatic behavior, we first validated the previous cytokine array data by ELISA (Figure 6A).