GDF9 and Infertility: When mice are experimentally rendered infertile by cyclophosphamide, treatment with conditioned medium and PRP was able to boost expression of ‘mothers against decapentaplegic’ homologs 1 and 2 (SMAD1, SMAD2), growth differentiation factor-9 (GDF9), and bone morphogenetic protein-15 (BMP15) [63].