The rare double-positive CD133+EpCAM+ cell subset was also present in six of the seven tumor samples at a 2.7 times higher proportion than in the healthy lung tissue [median values 0.1 (0.01–0.39 %) and 0.037 (0.01–0.0443 %), respectively; p = 0.16]. This evidence concerns the gene PROM1 and neoplasm.