Anthracycline drugs after their administration first of all affect the cells with active proliferation and differentiation resulting not only in inhibition of the processes but also in induction of apoptosis, that precisely explains the pathological shifts in the intestinal epithelium, i.e. in the tissue with many dividing and maturating cells. The damaged epithelium after the use of anthracycline drugs becomes permeable for many substance of the antigenic nature from the intestine lumen that stimulate the response of the lymphoid organs.