Absence of L-selectin on lymphoma cells prevents their growth in the thymuses of normal, but not L-selectin-deficient, C57BL/6 mice. (A, left) Representative thymic lymphoma harvested at necropsy after the injection of normal lymphoma or of L-selectin-deficient lymphoma to L-selectin-deficient mice. (Right) Thymus representative of a C57BL/6 mouse injected with L-selectin-deficient lymphoma after the same period of latency. (B) Genotype of thymic lymphoma cells induced on the intrathymic injection of lymphoma cells. Thymic lymphomas were harvested, and their genomic DNA was analyzed using the same primers as those used in Figure 1. Lane 1, 100-bp ladder; lane 2, thymic lymphoma harvested from normal C57BL/6 mice injected with 267 cells; lane 3, L-selectin-deficient C57BL/6 mice injected with 267 cells; lane 4, C57BL/6 mice injected with 1681 cells; lane 5, L-selectin-deficient C57BL/6 mice injected with 1681 cells; lane 6, L-selectin-deficient C57BL/6 mice injected with KOL1682 cells; lane 7, L-selectin-deficient C57BL/6 mice injected with KOL1677 cells.