Reconstitution of human thymus grafts with porcine class II⁺ cells in NOD/SCID-Tg mice given transplants of porcine BMCs plus human Thy/Liv tissues. (A,E) Normal human fetal thymus; (B,F) normal porcine thymus; (C-D,G-H) a human Thy/Liv graft removed at week 20 after implantation from a NOD/SCID-Tg mouse that received porcine BMCs and human Thy/Liv tissues. Panels A-C, HLA DR; E-G, SLA DR; D,H, isotype control. Original magnifications: × 20 (A-B, E-F); × 40 (C-D, G-H).