To induce HCC development, we delivered transposons expressing two oncogenes, NRASG12V and c-Myc, together with a Sleeping Beauty transposase (SB13) into C57BL/6-Foxp3tm1Flv/J mice expressing red fluorescent protein (RFP) regulatory T cells (Tregs) using the hydrodynamic tail vein injection (HDI) technique (Supplementary Figure S1A). The gene discussed is MYC; the disease is hepatocellular carcinoma.