The unique structure of Pyrrolobenzodiazepine (PBD) dimer contains two alkylated imines. In addition to monoalkylated adducts, it can also form inter-chain or intra-chain DNA cross-links, therefore Compared with PBD, it has greater DNA stability. Due to the possibility of other types of DNA adducts and higher adduct stability, C8-linked PBD dimers usually have significantly higher cytotoxicity, antitumor activity, and antibacterial activity than PBD monomers And one of the reagents, SJG-136, has entered clinical trials for stage II ovarian cancer and leukemia. In addition, because the related PBD dimer has significant cytotoxicity, it is currently being used as a payload of antibody-drug conjugates (ADC).