The properties of TT may also influence the effects on testosterone levels because of their pleiotropic effects such as: (i) direct action of the pituitary gland that secretes more LH; (ii) increased levels of dehydroepiandrosterone (DHEA) molecules; (iii) suppression of aromatase that prevents estrogen synthesis; (iv) antioxidant effect that protects against endothelial dysfunction in the gonads; (v) anti-inflammatory properties [8,46,64]. The gene discussed is PLOD1; the disease is endothelial dysfunction.