ESR1 and Crohn disease: By analyzing EXD targets, we hypothesize that EXD acts synergistically to mediate OP via calcium regulation and apoptosis, e.g., several studies have shown that ESR1 variants are related to postmenopausal OP [97–99], and ESR1 gene polymorphisms may be predictive of OP in female patients with Crohn's disease [65].