In the present study, expression of the previously proposed CSC membrane markers in pancreatic cancer (i.e. CD24+CD44+ESA+[16,44] and CD133+[17]) was not found upregulated in the PDAC xenograft SP, neither in microarray analysis, nor in flow-cytometric examination (1.0% CD133+ cells in the SP and 0.7% in the MP; n = 2) (data not shown). Here, CD44 is linked to pancreatic neoplasm.