ELP5 and bile duct cancer: Although we cannot rule out the mechanism by which gemcitabine stimulates Elongator activation in the present study, we hypothesize that the inhibitory activity of gemcitabine against DNA methyltransferases46 might demethylate the CpG island within the promoter region of Elongator subunit genes and activate transcription, as evidenced by the hypermethylation of the ELP3 promoter in tumor tissues47 and ELP5 genome loci in bile duct cancer cell lines from CCLE database21.