L-DOS47 was designed as a novel variation of antibody-directed enzyme prodrug therapy (ADEPT), in which the antibody component targets the molecule specific to its antigen—in this case, CEACAM6—on the tumor cell surface; however, unlike conventional ADEPT, in which prodrugs are administered systemically for the enzyme component to act upon, L-DOS47 uses the metabolite urea as a substrate, which is constitutively present in tumor tissues [37]. The gene discussed is CEACAM6; the disease is neoplasm.