The effects of PCAT-1 on MDR development in CRC cells were investigated by applying 5-fluorouracil (5-Fu) to Caco-2 and HT-29 cells; cells with PCAT-1 knocked down showed significantly lower viability after 5-Fu treatment than parental PCAT-1-expressing control cells [362]. This evidence concerns the gene PCAT1 and colorectal carcinoma.