Numerous approaches to the detection of novel biomarkers for male fertility have been proposed.As reviewed in the manuscript by Bieniek et al.1 analysis of seminal plasma has yielded numerous possible candidate biomarkers.Since semen analysis is a critical component in the initial workup for infertile males,seminal fluid biomarkers inherently have several distinct advantages.For most individuals,the sample is relatively easy to produce and,given an appropriate volume,can be separated into multiple aliquots for separate tests.Disadvantages include the fact that seminal fluid is a composition of excretions from multiple glands,including the seminal vesicles and prostate.