In the case of CYP3A4, CYP3A7, and CYP2E1 among Cytochrome P450 genes related to detoxicification of drug, HC iPSC and RA iPSC, which are undifferentiated cells, did not express well, but the markers were significantly increased in hepatocyte-like cells (Fig. 2k). This evidence concerns the gene CYP2E1 and rheumatoid arthritis.