CD44 and neoplasm: At the time of treatment discontinuation, despite the reduction in tumor size, tumors treated with 5-FU had higher protein levels of β-catenin and higher mRNA levels of the CSC markers LGR5, CD44, CD133, and CD166 than the untreated tumors; however, in the tumors co-treated with LGK-974 and 5-FU, the levels of β-catenin and CSC markers were not increased compared to untreated controls.