In 2017, Gou and colleagues described several heterozygous mutations in the D-box region of HIWI/PIWI-LIKE 1 gene of three out of 413 patients with idiopathic azoospermia, thereby impairing the ubiquitination of PIWI-LIKE 1 [27]. This evidence concerns the gene PIWIL1 and Azoospermia.