If it is unilateral, ultrasound or mammogram should be considered to exclude an underlying neoplastic process, If there is a clinical suggestion of hypogonadism based on the clinical history (decreased libido, erectile dysfunction) or evidence of testicular atrophy or gynecomastia a typical hormone panel would should include: total testosterone level, estradiol level, luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels at baseline, and gonadotrophin-releasing hormone (GnRH). The gene discussed is PLOD1; the disease is erectile dysfunction.