Schematic illustration of the new strategy to fight cancer using engineered Trojan-horse bacteria. (A) Illustration of the migration of cargo-carrying tumor-tropic bacteria toward a tumor. The outer cells (dark blue) are proliferating cells. The green cells represent dormant cancer stem cells (CSCs). Note that in real tumors the fraction of this subpopulation of cells is very low, and they can be widely scattered. The red cells are necrotic cells, and the light blue cells are stromal cells (see Ben-Jacob et al⁴  for more details). (B) Illustration of cargo-carrying Trojan-horse bacteria engineered to express antibodies targeting the tumor-specific antigens. This recognition enables the bacteria to enter the cells and inject the antitumor cargo.¹