KRT19 and neoplasm: We next evaluated the expression of CSC markers (EPCAM, PROM-1, THY1, CD24, ICAM1, KRT19, OCT4, NANOG, and SOX2) in these five paired samples (sphere and corresponding parental cells) by qRT-PCR and found that different marker expression patterns occurred in different primary tumor spheres (Fig. 2b).