Compositions and kits for modulating expression of scleraxis and/or collagen synthesis in mammalian cells and tissues. The compositions and kits comprise a protein comprising an amino acid sequence that shares at least 75% homology with SEQ ID NO:11. Proteins comprising amino acid sequences that share at least 75% homology with SEQ ID NO: 11 are expressed by mutants of scleraxis gene wherein a nucleotide sequence comprising a basic DNA binding domain has been deleted. Such mutants are exemplified by basic domain deletion ScxDeltaBD mutants that comprise nucleotide sequences sharing at least 75% homology with SEQ ID NO:8 or SEQ ID NO: 10. Methods for modulating fibrosis in a subject comprising administration of a composition comprising at least one physiologically effective dosage of a protein comprising a polypeptide molecule comprising an amino acid sequence that shares at least 75% homology with SEQ ID NO: 11.
