Similar results were found for LS174T human colorectal tumors in NOD/SCID mice; treatment with CPT-11 and either E. coli (lux/βG) or E. coli (lux) produced significant but similar suppression of tumor growth (Fig. 6B), indicating that therapeutic outcome was not affected by expression of beta-glucuronidase in E. coli (lux/βG). This evidence concerns the gene GUSB and colorectal neoplasm.