DHES0815A exerted promising anti-tumor activity against HER2-positive cancer cells (both direct- and bystander-killing effects) by the novel cleavable methyl-disulfide linker connected to DNA minor groove crosslinking agent, pyrrolo [2,1- c] [1,4] benzodiazepine monoamide (PBD-MA), the cytotoxic warheads with DAR: 2.0. This evidence concerns the gene ERBB2 and cancer.