PUM2 and Azoospermia: Based on few studies investigating PUM2 function, it is assumed that mammalian PUFs have physiological roles analogous to the non-vertebrate homologs: in germ cells, PUM2 interacts with deleted in azoospermia (DAZ), DAZ-like (DAZL) proteins, and the meiotic regulator BOULE (BOL), which are RBPs that function in early germ line stem cells [29], [31].