Salmonella as a basis for cancer therapy are theoretically extremely attractive because of the unique propensity to colonize solid tumors at a ratio (1000 to 10,000:1) that is much higher than the “natural” target organs of Salmonella colonization during an infection, namely the liver and spleen.2,13 We have extensive preclinical data that demonstrated that orally administered Salmonella-IL2 also possesses this unique property. Here, IL2 is linked to cancer.