When expressed in equivalent amount to WT hUSP26, hUSP26 L364F also stabilized RNF12 to some extent, but the variant’s stabilization of mRNF12 was not statistically significant compared to control cells not expressing hUSP26 (Fig. 7F), indicating that USP26 azoospermia variants may interfere with USP26 function in preventing RNF12 autoubiquitylation and proteasomal degradation. This evidence concerns the gene USP26 and Azoospermia.