Line F12444-3-2 was selected for inclusion in this study as an example of a line with very poor NPC differentiation quality; this line was unable to survive or expand following either MACS or FACS because the proportion of CD271-/CD133+ CD271-/CD133+ cells was very low (10.9% from 100% DAPI–live cells) (Fig 1B), and was therefore not included in the following experiments. This evidence concerns the gene PROM1 and nasopharyngeal carcinoma.