After a 3-month control period, patients were administered 200 mg/week of testosterone enanthate to inhibit LH and FSH for a total of 9 months and until successive sperm concentrations (performed twice monthly) showed azoospermia or severe oligozoospermia (mean sperm concentrations of <3 × 106 spermatozoa/mL) for 6 months. Here, PLOD1 is linked to Azoospermia.