The direct attachment to EB analogs has several advantages; (i) the well-established tumor-selective localization of EB/analogs thereof; (ii) EB analogs are highly chromophoric permitting facile quantification and simplifying tissue/tumor distribution studies; (iii) the resultant EB-BSH covalent complexes are relatively small molecules (~1250–1500 kDa) that generate the macromolecular agent in vivo upon tight non-covalent binding to serum albumin. The gene discussed is ALB; the disease is neoplasm.