Antibody-drug conjugates pair a tumor-targeting antibody with a potent cytotoxic payload, and the linker chemistry connecting them decides whether killing stays confined to the antigen-positive cell an ADC binds or spreads to neighboring cells. This simulation renders a 3D field of antigen-positive tumor cells and antigen-negative bystander cells with free ADC molecules diffusing through the extracellular space, binding surface antigen, internalizing, and releasing payload according to the linker you select. A cleavable linker frees a membrane-permeable payload that diffuses into and kills neighboring cells regardless of their own antigen status — the bystander effect used by drugs like trastuzumab deruxtecan — while a non-cleavable linker keeps the cytotoxic effect confined to the cell that internalized the ADC, as with T-DM1. Adjust antigen density, drug-antibody ratio and diffusion radius and watch the live kill counts for target versus bystander cells.