Approximately at the time when Osoba and Miller1 described the thymic factor and indicated that through this factor thymus endows the lymphoid cells with power to participate in the phenomenon of immunity, Perri et al2 spoke about thymus as follows:
The thymus and its function could be of particular importance in the field of oncology since it might participate, along with other glands, in the regulation of tissue homeostasis and be of paramount importance in regressing the activity of cells which potentially may develop into neoplasms.
Perri et al found that Jensen sarcoma grew at a faster rate in thymectomized animals than in normal controls. Since that time, other authors have indicated that in animals and in humans who have been immunosuppressed, the incidence of malignant tumors was higher than in those with normal immunity status.
In 1972, Penn and Starzl3 demonstrated that human organ transplant recipients