GPC2 and endometriosis: Importantly, these splicing-active SNPs had molecular trait effects in the brain (substantia nigra) (GPC2), skeletal muscle (AC113189.5, SAT2, FXR2), whole blood (TNFSF13, FXR2), thyroid (SAT2, FXR2), adipose (SAT2, AC113189.5) and other organs which may suggest they play a significant role in the mechanisms of endometriosis development.