Direct conjugation of doxorubicin with a fragment of AFP using an acid labile linkage [31] resulted in conjugates with high toxicity towards doxorubicin-sensitive SKOV3 cells as well as doxorubicin-resistant SLVB ovarian cancer cells while showing low toxicity to normal lymphocytes compared to doxorubicin. The gene discussed is AFP; the disease is ovarian cancer.