Human ASCL1, POU3F2 (aka BRN2), and MYT1L cDNAs were separately cloned into the lentiviral vector pHRST-IRES-GFP, which contains an IRES-EGFP cassette under the control of a CMV promoter. The lentivirus envelope plasmid pMD.2G-VSV G and the packaging plasmid pCMVdeltaR8.2 were purchased from Addgene (plasmid 12259 and 12263, respectively) 50 (link). Lentivirus was generated for all three human plasmids as described below. The reprogramming efficiency of the different fibroblast lines should be independent of the age and gender of the patient 51 (link).