EFS and malignant colon neoplasm: We observed that the Salmonella Δcas3 strain exhibited lower invasion to mouse macrophage cells MH-S and RAW264.7, human colon cancer cells SW480 and SW620, and porcine small intestinal epithelial cells IPEC-J2 than the cas3 WT and Δcas3/p-cas3 strain (Figure 3A–E).