Farmer's lung: The so-called farmer's lung is a disease caused by a hypersensitivity. The cause is a reaction of IgG antibodies to large quantities of inhaled antigens in the alveolar walls of the lungs. It leads to an inflammation of the alveolar walls and impairs breathing.

FK 506 is a substance which deactivates T cells. FK 506 and Cyclosporin A are the most commonly used immunosuppressives which are administered for organ transplants. The rejection reaction can be largely suppressed by their use.

Foetal erythroblastosis: Foetal erythroblastosis is a serious form of Rhesus haemolysis in which maternal anti-Rh antibodies are transferred to the foetus via the placenta, react to paternal antigens on the foetal erythrocytes and trigger a haemolytic anaemia. This is so serious that the peripheral blood of the foetus contains almost all immature erythroblasts.

Fungi, such as the one-cell eukaryotic yeasts or the moulds, can cause a number of types of illnesses. The immune responses to fungi are complex and made up of humoral and cellular reactions.