However, some of the diabodies (HL/LH-42, HL/LH-45, and LH-48), which caused only minimal damage to cancer cells in the direct MTS assay of culture supernatant (Fig. 1), showed distinct cytotoxicity when purified and assayed at concentrations of 10 or 100 nM (Fig. 2), probably because the expression level of the diabodies in culture supernatant was low. The gene discussed is PLOD1; the disease is cancer.