Answers are grounded in this paper and cite their sources.
Supernatant fluids of specifically stimulated lymphocyte cultures were purified. Fractions containing migration inhibition factor when injected intra-dermally into strain-2 guinea pigs produced a reaction similar in appearance to delayed cutaneous hypersensitivity. There was an accumulation of mononuclear cells at the injection sites and the growth of syngeneic tumor grafts at the sites was suppressed.
No takes yet. Share an insight, caveat, or question.
Bernstein et al. (1971) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: