CD44 and pancreatic neoplasm: For instance, Fu et al. found that CSCs labeled with CD133+, ESA+, CD24+, CD44+ isolated from primary pancreatic tumor specimens expressed negligible levels of DR4 and DR5; however DR4 and DR5 were upregulated by inhibition of hedgehog signaling and, in humanized SCID mice, this led to slowing of tumor growth [30].