It's not the only paper I read regarding IPSC and germ cell induction. The Yamanaka paper has been out since 2007, this kind of work is well established. But, this paper is the only one I can find that has researchers attempting to make sperm from a female. There are other papers regarding iPSCs induced to become female germ cells to oocytes and then IVF producing viable offspring, in mouse, pig, and monkey.