Involution of the thymus dependent lymphoid system.
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D001835:Body Weight; D006087:Graft vs Host Reaction; D017710:Lymphocyte Transfusion; D008214:Lymphocytes / Q000276:immunology*; D051379:Mice; D008805:Mice, Inbred A; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008814:Mice, Inbred NZB; D009929:Organ Size; D016038:Skin Transplantation; D013045:Species Specificity; D013154:Spleen / Q000166:cytology; D013934:Thymectomy; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology* / Q000637:transplantation; D014184:Transplantation, Homologous