LEFTY2 is a member of the TGF-beta family of proteins. The protein is secreted and plays a role in left-right asymmetry determination of organ systems during development. The protein may also play a role in endometrial bleeding. Mutations in its gene have been associated with left-right axis malformations, particularly in the heart and lungs. Some types of infertility have been associated with dysregulated expression of its gene in the endometrium.