Soon afterwards, the Yamanaka lab, as well as other labs, used the human orthologs of these four transcription factors (OCT4, SOX2, c-MYC, KLF4), or OCT4, SOX2, NANOG and LIN28, to generate human iPSCs and patient- specific iPSCs with different diseases, including PD [86–88]. This evidence concerns the gene KLF4 and Parkinson disease.