Histologic analysis of liver. T cells from unprimed C57BL/6 mice were transplanted into lethally irradiated BALB/c mice along with T cell–depleted bone marrow cells. Biopsies were obtained on day +26. Hematoxylin and eosin; original magnification × 100. (A) TCD BM only. (B) Unseparated. (C) CD62L⁺. (D) CD62^–.