Nonobstructive azoospermia (NOA) is a substantial challenge in the management of male infertility. Currently, the therapeutic approach primarily focuses on sperm retrieval by micro-dissection testicular sperm extraction (micro-TESE). However, the success rate of surgical sperm retrieval (SSR) is only around 50%. Thus, half of the men undergo a traumatic, potentially harmful, expensive surgery without gaining any benefit, and without any further therapeutic option. Thus, there is still a need for major innovations in the evaluation and management of NOA.