gly val leu or ile glu may be substituted with asp gly may be substituted with ala val leu or ile and or leu may be substituted with ala val gly or ile in some embodiments of the invention the compound is cys arg arg ala asn ala dcys it is contemplated that one or more of the amino acids in this compound may be deleted or substituted with a conservative substitution such as for example cys may be substituted with penicillamine dcys or dpenicillamine one or both of the ala residues may be substituted independently with gly val leu or ile asn may be substituted with gln and or dcys may be substituted with dpenicillamine cys or penicillamine in some embodiments peptides of the present invention comprise one or more d amino acids as used herein the term 34 d amino acid peptides 34 is meant to refer to peptides according to the present invention which comprise at least one and preferably a plurality of d amino acids d amino acid peptides retain the biological activity of the peptides of the invention that consist of l amino acids i e d amino acid peptides inhibit tnf u03b1 in some embodiments the use of d amino acid peptides is desirable as they are less vulnerable to degradation and.