Additional information about the role of MFN1 in this process has been given by the demonstration that this protein interacts with GASZ, a germ cell-specific protein with a mitochondrial targeting sequence that leads to its dimerization at the OMM and to its collaboration with MFN1 to promote the fusion process; GASZ loss has been shown to cause male infertility [145]. This evidence concerns the gene ASZ1 and male infertility.