Moreover, we have recently demonstrated, for the first time, that HDACi vorinostat in combination with capecitabine produces a synergistic antitumor effects by up-regulating, in vitro and in vivo, in colorectal cancer cells but not in ex vivo treated peripheral blood lymphocytes, the mRNA and protein expression of thymidine phosphorylase (TP), the key enzyme converting capecitabine to 5-FU[2]. Here, TYMP is linked to colorectal cancer.