1. From the point of view of immunology

See also: immunological

• family Tuberculariaceae
• family Tulostomaceae
• family Tulostomataceae
• family Tupaiidae
• family Turdidae
• family Turnicidae
• family Tylenchidae
• family Typhaceae
• family Typhlopidae
• family Tytonidae
• family Uintatheriidae
• family Ulmaceae
• family Ulvaceae
• family Umbelliferae
• family Unionidae
• family unit
• family Upupidae
• family Uranoscopidae
• family Ursidae
• family Urticaceae
• family Usneaceae
• family Ustilaginaceae
• family Valerianaceae
• family Varanidae
• family Veneridae