 Even in bound mutant AR, NTD antagonists would be able to block the AF2 function via direct surface interaction, regardless of the ligand bound.Research on these NTD antagonists are usually carried out by affinity screening of phage display libraries that express random peptides containing various signature motifs.ARs seem to have a distinct preference for ‘FxxLF’ type of binding motifs (where F = phenylalanine, L = leucine, and X = any amino acid residue), whereas other nuclear receptors have a highly similar binding mechanism for ‘LxxLL’ type of binding motifs.