Zhang W, Zhang Y, Zhao M, et al. - This study was attempted to explore microRNA (miRNA) expression profiles in the seminal plasma of nonobstructive azoospermia (NOA) patients with different histopathologic patterns and evaluate potential noninvasive diagnostic biomarkers of NOA using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Researchers included 13 individuals with NOA (7 Sertoli cell-only syndrome and 6 hypospermatogenesis to spermatogenesis arrest) and 7 normal fertile controls for sequencing, six samples per group for validation; 54 patients with NOA (27 SCOS and 27 SA) and 19 normal fertile controls for large-sample qRT-PCR analysis. In comparison with normal fertile controls, microRNA expression profiles in seminal plasma were altered in patients with NOA. It has been reported that the profiles differed in patients with NOA with different pathologic patterns. The outcomes highlighted that miR-34c-5p in seminal plasma could be a potential noninvasive biomarker to diagnose patients with NOA and identify different pathologic types of NOA. The results considered that the Notch signaling pathway may be involved in the pathogenesis of NOA.