Kim et al. [51] evaluated ER expression in the FT fibroblasts and FT synovial lining cells of postmenopausal idiopathic CTS women (study group) and postmenopausal women without CTS (control group), concluding that the ERα and ERβ labeling indexes were higher in the study than in the control group for both cell types (p < 0.001). This evidence concerns the gene ESR1 and carpal tunnel syndrome.