Utilizing a xenograft model of primary pancreatic adenocarcinoma, Li et al. purified a subpopulation of CD44+CD24+ESA+ pancreatic cancer cells (approximately 0.2%–0.8% of the total cell number) that demonstrated the requisite CSC properties of self-renewal, tumorigenic capacity, and production of phenotypically diverse progeny [33]. The gene discussed is CD44; the disease is pancreatic neoplasm.