?-AI from the GM pea, in particular comparing post-translational modifications (eg glycosylation patterns). Using a finer detection method, Campbell could show that structural variation of the ?-AI is common and they suggest that the variation(s) found in GM pea fits within the variable range found amongst beans. However, this does not allow the conclusion that any one of the variant proteins is or is not allergenic or immunogenic. This needs testing. Even small differences/variations can have very different effects. And here is the challenge and the striking difference between the papers. Whilst Prescott et al (2005, 2006) have developed a strong and workable model by using oral exposure (eg feeding trials or administering food directly into the stomach) to test for food allergens and immunogens, Campbell et al only use injections into the body cavity (intra-peritoneal) to sensitize the mice and compare immune responses (here Th1 and Th2 antibody isotype responses). Intra-peritoneal injections are generally used in other contexts, in particular in animal testing of systemic drugs, when the drug is supposed to be delivered throughout the body. It is also used to sensitise the body to a substance, eg the injection with a purified substance is a bit like a vaccine, it warns the immune system. Next time when the same compound comes along the immune system will remember. Campbell et al. were using the same specific mice (BALB/c) as Prescott. If the authors thought (though wrongly) that Prescott only used pinto bean and failed to use the Tendergreen