The present invention provides a peptide that selectively binds αvβ6 integrin, the peptide having an amino acid sequence comprising the motif X1BnRGDLX2X3X4ZmX5, wherein X1 is any D-amino acid, Bn is a sequence of any n amino acids, which may be natural or unnatural, D- or L-, and may be the same or different, wherein n is a number between 1 and 10, X2 and X3 are independently selected from any amino acid, X4 is Leu or Ile, Zm is a sequence of any m amino acids, which may be natural or unnatural, D- or L-, and may be the same or different, wherein m is a number between 1 and 10, X5 is any L- or D-amino acid. Also provided are conjugates comprising said peptide, pharmaceutical compositions comprising said peptide or said conjugates, and uses of said peptide, conjugate or composition, for example, in the treatment, imaging and/or diagnosis of an αvβ6-expressing tumour in a mammalian subject.
