The process for the production of a dimeric, biologically active Transforming Growth Factor type .beta. (TGF-.beta.)-like protein or a salt thereof, comprising refolding the denatured monomeric form of the protein in the presence of a mild detergent that permits folding of the monomeric protein into a spatial conformation, which after dimerization, is the conformation associated with the biological activity, while retaining the monomeric protein in soluble form. Mild detergents include sulfobetaines, 3-(3-chlolamidopropyl)dimethylammonio-1-propanesulfonate, 3-(3-chlolamidopropyl)dimethylammonio-2-hydroxy-1-propane-sulfonate, digitonin, cholate and deoxycholate at a concentration of about 1 to 100 mM. Compositions containing a TGF-.beta.-like protein produced according the invention can be used for the promotion and acceleration of wound healing and bone and tissue repair, cancer treatment, bone marrow protective agent, as a mediator of cardio-protection, as an anti-inflammatory or immunosuppressive agent, or as a growth regulator in mammalian cell cultures.