MOV10L1 is an ATP-dependent RNA helicase essential for germline integrity and spermatogenesis. Its primary function is to process piRNA precursors through 5'-3' RNA unwinding activity, facilitating generation of intermediate piRNA fragments that are subsequently loaded onto Piwi proteins 1. MOV10L1 operates within the piRNA metabolic pathway to suppress transposable element mobilization via piRNA-mediated DNA methylation and silencing 1. Mechanistically, MOV10L1 specifically binds piRNA precursors and promotes their unwinding and funneling to PLD6 endonuclease, which catalyzes initial piRNA cleavage 2. The protein functions in both primary and secondary (ping-pong cycle) piRNA processing 1. MOV10L1 deficiency causes meiotic arrest and male sterility through de-repression of retrotransposons and defective piRNA biogenesis 2. Recent evidence demonstrates that piRNA pathway dysfunction affects both sexes; Mov10l1-knockout female hamsters exhibit oocyte developmental failure, contrary to mouse models 3. Clinically, MOV10L1 polymorphisms are significantly associated with male infertility in men with complete spermatogenic maturation arrest 4, and deleterious variants have been identified in infertile patients through whole-exome sequencing 5. Additionally, MOV10L1 polymorphisms on chromosome 22 show genetic linkage to integrated human herpesvirus-6 sequences, suggesting roles in suppressing viral genome integration 6.