Definition: Humoral factors secreted by the thymus gland. They participate in the development of the lymphoid system and the maturation of the cellular immune response.
Ann NY Acad Sci 1979;332:172; Ann NY Acad Sci 1979;332:9; Clin Immunol Immunopathol 1980;15(4):646; FEBS Lett 90(2):239;1978; Geriatrics 32(7):101;1977