Azoospermic men attending microdissection testicular sperm extraction (MD-TESE) are group A. Second group (B) is the men with poor semen quality, who are treated with aromatase inhibitor, antiestrogen or human choriogonadotropic hormone (HCG) to improve semen quality. Third group (C) consists of men submitting semen analysis. The intended number of participants is 60, 60 and 100 men, respectively.