5-Fluorodeoxyuridine, 5-fluorodeoxyuridine, 5-fluorouracil, Colorectal Cancer, Colorectal Cancer Cells, DNA, DNA repair enzyme, FU, FdU, Fluorouracil, Human, Human Uracil DNA Glycosylase, RTX, Raltitrexed, Uracil, advanced colorectal cancer, cancer, cancer cell, cancer cell lines, cancers, cell lines, colorectal, colorectal cell lines, colorectal lines, dT, deoxynucleoside, deoxyuridine, deoxyuridine triphosphate, doxycycline, doxycycline-inducible promoter, fluorouracil, hUNG, human, human uracil DNA glycosylase, p53, pyrimidine, raltitrexed, short, thymidylate synthase, thymine, thymine DNA glycosylase, uracil, uracil DNA glycosylase