After demonstrating that the increase in MDR1 mRNA levels due to iDHACs treatment did not correspond with an increase in Pgp protein expression or activity, and since these results resembled our previous findings in colon carcinoma cell lines [19], we decided to determine whether the MDR1 mRNA present in pancreatic carcinoma cell lines included the longer or the shorter 5′ UTR form (Figure 2A), and whether the translational control was a general phenomenon in pancreatic cancer cells. This evidence concerns the gene ABCB1 and colon carcinoma.