Increased incidence of lymphoma after injections of mice with cells differing at weak histocompatibility loci.

Newborns of two congenic strains of mice, in which the incidence of leukemia is low, differing only at the weak H-1 locus, were. injected at birth with adult spleen cells of the parent and of the congenic strain. A marked increase in the incidence of lymphoma ensued in those mice of both strains injected with cells from the other strain. The experiment lends some support to the idea that transplantation immunologic mechanisms may play a role in the genesis of lymphomas.