Abstract: The present disclosure relates to a pharmaceutical composition for use in the preventive and/or therapeutic treatment of thrombosis-related diseases or conditions relating to high level of plasminogen activator inhibitor 1 (PAI-1) expression, which composition comprises: A) a fragment of a polypeptide or protein of prolactin (PRL)-growth hormone (GH)-placental lactogen (PL)-family and homologous derivatives thereof, which fragment comprises from 6 to 14 consecutive amino acid residues of the amino acid sequence having general formula (I); or B) a peptide or a recombinant protein comprising said peptide, wherein the peptide is from 6 to 50 amino acids in length and has the activity to inhibit PAI-1, said peptide comprising from 6 to 14 consecutive amino acid residues of the amino acid sequence of general formula (I); or C) a polynucleotide encoding said fragment of a polypeptide or protein of A) or said peptide or recombinant protein of B).