KLK3 and hypogonadism: In 21 (22.3%) male recipients with hypogonadism, testosterone substitution was not started: in 14 (14.9%) because of mild clinical manifestation of hypogonadism and expected spontaneous improvement, in 4 (3.3%) due to increased prostate specific antigen, and in 3 (2.4%) as a result of the patient’s personal preference.