Although the localization of MVH/DDX4 is normal in Mili mutant, MVH/DDX4 is essential for the maturation of MILI cleaved pre-piRNA intermediates depending on its ATPase activity; thus by involving the ping-pong cycle, loss of ATPase activity leads to male infertility displaying piRNA intermediate accumulation and transposon activation [28]. Here, DDX4 is linked to male infertility.