GPD2 and Infertility: While other investigators had erroneously assumed that loss of Immp2L peptidase activity caused complete loss of Gpd2 enzyme activity and cellular senescence [8], infertility, neurodegeneration and early aging [4,5,6,7] in the present study we report that Gpd2 is not inactivated when Immp2l is knocked-out and we find no evidence of cellular senescence, infertility, neurodegeneration, oxidative stress or early aging in the Immp2lKD−/− KO mouse [3,9,10,11].