Abstract: An isolated or purified nucleic acid molecule consisting essentially of a nucleotide sequence encoding KLH or a fragment thereof, as well as an isolated or purified nucleic acid molecule consisting essentially of a nucleotide sequence complementary thereto; a vector comprising such a nucleic acid, optionally as part of an encoded fusion protein when the nucleic acid encodes KLH or a fragment thereof; a cell comprising and expressing an above-described nucleic acid, optionally in the form of a vector; an isolated or purified polypeptide molecule consisting essentially of an amino acid sequence encoding KLH-1, KLH-2, or a fragment of either of the foregoing, as well as a conjugate or fusion protein comprising the same and a therapeutically or prophylactically active agent, and related compositions; a method of treating cancer, pathogenic infection, and high blood pressure in a mammal; methods of stimulating an immune response in a mammal; a method of identifying an immunogenic portion of KLH, and an isolated or