 Even at the highest observed concentrations found in wheat gluten, the melamine exposure is much smaller than the rat and mouse doses for which effects were seen.Instead, the FDA has suggested a second contaminant may be responsible for the ill effects and melamine, as the most easily identifiable contaminant, may serve as a biomarker, or indicator, for contaminated wheat gluten.According to the FDA, "the association between melamine in the kidneys and urine of cats that died and melamine in the food they consumed is undeniable.