PPP1CC and Infertility: Because our earlier attempts to rescue the Ppp1cc −/− infertility phenotype failed [24], we developed mouse lines where transcription of transgenic mouse Ppp1cc2 cDNA was driven by the endogenous 2.6-kb region immediately upstream of the transcription start site of the Ppp1cc gene (hereafter called the endogenous Ppp1cc promoter) (Fig. 1A).