So, given the growth advantage and the drug resistance phenotype of MC38-FUT9 when cultured in 3D, we hypothesized that in heterogeneous tumor specimens 5-FU treatment would potentially enrich for low-abundance FUT9+ cells bearing a CSC-like phenotype, as stem cells (rare cell population) are assumed to accumulate in patients undergoing chemotherapy. This evidence concerns the gene FUT9 and neoplasm.