“…CD44, a specific receptor for hyaluronic acid and adhesion/homing molecule (Naor et al, 2008;Jaggupilli and Elkord, 2012), is a multifunctional class I transmembrane glycoprotein expressed in almost all normal and cancer cells (Naor et al, 2008;Jaggupilli and Elkord, 2012). In several previous studies, CD44 individually or in combination with other putative CSC markers has been applied to isolate CSCs in various solid tumors including breast (Al-Hajj et al, 2003), prostate, pancreas (Immervoll et al, 2011), ovarian, colorectal (Wielenga et al, 1993;Woodman et al, 1996;Choi et al, 2009), head and neck (Satpute et al, 2013) and bladder cancers (Yang and Chang, 2008;Chan et al, 2009;Slomiany et al, 2009;Lee et al, 2010;Su et al, 2010;Jaggupilli and Elkord, 2012). Both in vitro and in vivo studies have shown that CD44+ bladder cancer cells have higher tumorigenic potential compared to CD44-bladder cancer cells; whereas they have lower tumorigenic potential compared to ALDH1A1+ cells .…”