PLOD1 and Testicular atrophy: Interestingly and perhaps unsurprisingly, two of the three dunnarts with ETL also had concurrent testicular degeneration, which would lead to low circulating testosterone levels and, subsequently, supraphysiologic luteinizing hormone (LH) levels due to the absence of negative feedback to the hypothalamus and anterior pituitary axis, as would happen in gonadectomized animals.