A peptide or peptidomimetic of 25 residues or less that inhibits human galectin-7 dimerization, said peptide comprising: (i) a domain comprising the sequence of formula II: Xaa 14 -Xaa 15 -Xaa 16 -Xaa 17 -Xaa 18 -Xaa 19 -Xaa 20 wherein "-" represents a bond; Xaa 14 is L-Leu or D-Leu; Xaa 15 is L-Asp or D-Asp; Xaa 16 is L-Ser or D-Ser; Xaa 17 is L-Val or D-Val; Xaa 18 L-Arg or D-Arg; Xaa 19 is L-Ile or D-Ile; Xaa 20 is L-Phe or D-Phe; or a domain comprising the sequence of formula II in which one of Xaa 16, Xaa 18 or Xaa 20 is substituted (ii) a domain comprising the sequence of formula I: Xaa 1 -Xaa 2 -Xaa 3 -Xaa 4 -Xaa 5 -Xaa 6 -Xaa 7 -Xaa 8 -Xaa 9 -Xaa 10 -Xaa 11 -Xaa 12 -Xaa 13 "-" represents a bond Xaa 1 is L-Ile or D-Ile; Xaa 2 is L-Arg or D-Arg; Xaa 3 is L-Pro or D-Pro; Xaa 4 is Gly; Xaa 5 is L-Thr or D-Thr; Xaa 6 is L-Val or D-Val; Xaa 7 is L-Leu or D-Leu; Xaa 8 is L-Arg or D-Arg; Xaa 9 is L-Ile or D-Ile; Xaa 10 is L-Arg or D-Arg; Xaa 11 is Gly; Xaa 12 is L-Leu or D-Leu; Xaa 13 is L-Val or D-Val; or (iii) a domain comprising the sequence of formula IIIA or IIIB: Xaa 21 -Xaa 22 -Xaa 23 -Xaa 24 -Xaa 25 -Xaa 26 -Xaa 27 -Xaa 28 -Xaa 29 -Xaa 30 -Xaa 31 -Xaa 32 -Xaa 33 -Xaa 34 -Xaa 35 -Xaa 36 -Xaa 37 (IIIA): Xaa 30 -Xaa 31 -Xaa 32 -Xaa 33 -Xaa 34 -Xaa 35 -Xaa 36 -Xaa 37 -Xaa 38 -Xaa 39 -Xaa 40 -Xaa 41 -Xaa 42 -Xaa 43 (IIIB): wherein "-" is a bond; Xaa 21 is L-Phe or D-Phe; Xaa 22 is L-Glu or D-Glu; Xaa 23 is L-Val or D-Val; Xaa 24 is L-Leu or D-Leu; Xaa 25 is L-Ile or D-Ile; Xaa 26 is L-Ile or D-Ile; Xaa 27 is L-Ala or D-Ala; Xaa 28 is L-Ser or D-Ser; Xaa 29 is L-Asp or D-Asp; Xaa 30 is L-Asp or D-Asp; Xaa 31 is Gly; Xaa 32 is L-Phe or D-Phe; Xaa 33 is L-Lys or D-Lys; Xaa 34 is L-Ala or D-Ala; Xaa 35 is L-Val or D-Val; Xaa 36 is L-Val or D-Val; Xaa 37 is Gly; Xaa 38 is L-Asp or D-Asp; Xaa 39 is L-Ala or D-Ala; Xaa 40 is L-Gln or D-Gln; Xaa 41 is L-Tyr or D-Tyr; Xaa 42 is L-His or D-His, and Xaa 43 is L-His or D-His; or a salt thereof. (i) a domain comprising the sequence of formula II: Xaa 14 -Xaa 15 -Xaa 16 -Xaa 17 -Xaa 18 -Xaa 19 -Xaa 20 wherein "-" represents a bond; Xaa 14 is L-Leu or D-Leu; Xaa 15 is L-Asp or D-Asp; Xaa 16 is L-Ser or D-Ser; Xaa 17 is L-Val or D-Val; Xaa 18 L-Arg or D-Arg; Xaa 19 is L-Ile or D-Ile; Xaa 20 is L-Phe or D-Phe; or a domain comprising the sequence of formula II in which one of Xaa 16, Xaa 18 or Xaa 20 is substituted "-" represents a bond; Xaa 14 is L-Leu or D-Leu; Xaa 15 is L-Asp or D-Asp; Xaa 16 is L-Ser or D-Ser; Xaa 17 is L-Val or D-Val; Xaa 18 L-Arg or D-Arg; Xaa 19 is L-Ile or D-Ile; Xaa 20 is L-Phe or D-Phe; (ii) a domain comprising the sequence of formula I: Xaa 1 -Xaa 2 -Xaa 3 -Xaa 4 -Xaa 5 -Xaa 6 -Xaa 7 -Xaa 8 -Xaa 9 -Xaa 10 -Xaa 11 -Xaa 12 -Xaa 13 "-" represents a bond Xaa 1 is L-Ile or D-Ile; Xaa 2 is L-Arg or D-Arg; Xaa 3 is L-Pro or D-Pro; Xaa 4 is Gly; Xaa 5 is L-Thr or D-Thr; Xaa 6 is L-Val or D-Val; Xaa 7 is L-Leu or D-Leu; Xaa 8 is L-Arg or D-Arg; Xaa 9 is L-Ile or D-Ile; Xaa 10 is L-Arg or D-Arg; Xaa 11 is Gly; Xaa 12 is L-Leu or D-Leu; Xaa 13 is L-Val or D-Val; or "-" represents a bond Xaa 1 is L-Ile or D-Ile; Xaa 2 is L-Arg or D-Arg; Xaa 3 is L-Pro or D-Pro; Xaa 4 is Gly; Xaa 5 is L-Thr or D-Thr; Xaa 6 is L-Val or D-Val; Xaa 7 is L-Leu or D-Leu; Xaa 8 is L-Arg or D-Arg; Xaa 9 is L-Ile or D-Ile; Xaa 10 is L-Arg or D-Arg; Xaa 11 is Gly; Xaa 12 is L-Leu or D-Leu; Xaa 13 is L-Val or D-Val; or (iii) a domain comprising the sequence of formula IIIA or IIIB: Xaa 21 -Xaa 22 -Xaa 23 -Xaa 24 -Xaa 25 -Xaa 26 -Xaa 27 -Xaa 28 -Xaa 29 -Xaa 30 -Xaa 31 -Xaa 32 -Xaa 33 -Xaa 34 -Xaa 35 -Xaa 36 -Xaa 37 (IIIA): Xaa 30 -Xaa 31 -Xaa 32 -Xaa 33 -Xaa 34 -Xaa 35 -Xaa 36 -Xaa 37 -Xaa 38 -Xaa 39 -Xaa 40 -Xaa 41 -Xaa 42 -Xaa 43 (IIIB): wherein "-" is a bond; Xaa 21 is L-Phe or D-Phe; Xaa 22 is L-Glu or D-Glu; Xaa 23 is L-Val or D-Val; Xaa 24 is L-Leu or D-Leu; Xaa 25 is L-Ile or D-Ile; Xaa 26 is L-Ile or D-Ile; Xaa 27 is L-Ala or D-Ala; Xaa 28 is L-Ser or D-Ser; Xaa 29 is L-Asp or D-Asp; Xaa 30 is L-Asp or D-Asp; Xaa 31 is Gly; Xaa 32 is L-Phe or D-Phe; Xaa 33 is L-Lys or D-Lys; Xaa 34 is L-Ala or D-Ala; Xaa 35 is L-Val or D-Val; Xaa 36 is L-Val or D-Val; Xaa 37 is Gly; Xaa 38 is L-Asp or D-Asp; Xaa 39 is L-Ala or D-Ala; Xaa 40 is L-Gln or D-Gln; Xaa 41 is L-Tyr or D-Tyr; Xaa 42 is L-His or D-His, and Xaa 43 is L-His or D-His; or a salt thereof. wherein "-" is a bond; Xaa 21 is L-Phe or D-Phe; Xaa 22 is L-Glu or D-Glu; Xaa 23 is L-Val or D-Val; Xaa 24 is L-Leu or D-Leu; Xaa 25 is L-Ile or D-Ile; Xaa 26 is L-Ile or D-Ile; Xaa 27 is L-Ala or D-Ala; Xaa 28 is L-Ser or D-Ser; Xaa 29 is L-Asp or D-Asp; Xaa 30 is L-Asp or D-Asp; Xaa 31 is Gly; Xaa 32 is L-Phe or D-Phe; Xaa 33 is L-Lys or D-Lys; Xaa 34 is L-Ala or D-Ala; Xaa 35 is L-Val or D-Val; Xaa 36 is L-Val or D-Val; Xaa 37 is Gly; Xaa 38 is L-Asp or D-Asp; Xaa 39 is L-Ala or D-Ala; Xaa 40 is L-Gln or D-Gln; Xaa 41 is L-Tyr or D-Tyr; Xaa 42 is L-His or D-His, and Xaa 43 is L-His or D-His;