**3.2 Studies with human PBMCs**

The phenomenon of radioadaptive response has been reported in human lymphocytes in various studies (Table 1). The advantages of the lymphocytes as a model to understand the low dose ionizing radiation response is due to their radiosensitivity. More over, the lymphocytes are found in circulating peripheral blood and therefore, can be easily obtained from peripheral venous blood. These cells involved in cell mediated immunity as well as humoral immunity and cell proliferation and their radiosensitivity is similar to that of proliferating cells of the hematopoetic tissue.
