To assess the effect of PCs inhibition by Spn4A on tumorigenicity of colon cancer cells, four groups of nude mice (n=6) were subcutaneously inoculated with HT-29/CTL, CT-26/CTL, HT-29/Spn4A or CT-26/Spn4A cells. This evidence concerns the gene DDX53 and malignant colon neoplasm.