Piwi-like protein 2 (PIWIL2) plays a central role during spermatogenesis by repressing transposable elements and preventing their mobilization, which is essential for the germline integrity. PIWIL2 plays an essential role in meiotic differentiation of spermatocytes, germ cell differentiation and in self-renewal of spermatogonial stem cells. PIWIL2 acts via the piRNA metabolic process, which mediates the repression of transposable elements during meiosis by forming complexes composed of piRNAs and PIWI proteins. PIWIL2 directly binds piRNAs, a class of 24 to 30 nucleotide RNAs that are generated by a Dicer-independent mechanism and are primarily derived from transposons and other repeated sequence elements.