Figure 5B illustrates that all cells in culture are efficiently eliminated when only 40% of cells in population express HSV-TK (unsorted kiPS HSV-TK population). These data are consistent with our previous observations in rhabdomyosarcoma, where only 20% of HSV-TK expressing cells in population were enough to eradicate basically every cell in the culture by ganciclovir treatment [29]. The gene discussed is TKT; the disease is rhabdomyosarcoma.