Discovered about two decades ago, piRNAs are a large and versatile type of sncRNA and that remain insufficiently identified and analyzed, through next-generation sequencing (NGS), to evaluate their processing, functions, and biogenesis in different cell types and during development. piRNAs’ distinction from other sncRNAs has led to controversial results and interpretation difficulties when using existing databases because of the heterogeneity of the criteria used in making the distinction. |