Progression of AB42 to a Toxic Dodecamer (IMAGE) University of California - Santa Barbara Caption This illustrates the progression of AB42 to a toxic dodecamer, or, "twelve-mer" aggregation, (blue -- above). Below, the AB40 oligomer only becomes a nontoxic tetramer aggregation. Credit UCSB Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.