Peptidomimetic foldamers often break the previously mentioned definition of foldamers as they often adopt helical structures.  They represent a major landmark of foldamer research due to their design and capabilities.  The largest groups of peptidomimetic consist of β-peptides, γ-peptides and δ-peptides, and the possible monomeric combinations. The amino acids of these peptides only differ by one (β), two (γ), or three (δ) methylene carbons, yet the structural changes were profound. These peptide sequences are highly studied as sequence control leads to reliable folding prediction. Additionally, with multiple methylene carbons between the carboxyl and amino termini of the flanking peptide bonds, varying R-group side chains can be designed. One example of the novelty of β-peptides can be seen in the findings of Reiser and coworkers.  Using a heteroligopeptide consisting of α-amino acids and cis-β-aminocyclopropanecarboxulic acids (cis-β-ACCs), they found the formation of helical sequences in oligomers as short as seven residues and defined conformation in five residues, a quality unique to peptides containing cyclic β-amino acids.