long term problems associated with future immunological methods of fertility control include the following : ( 1 ) reversibility , ( 2 ) unscrupulous use , ( 3 ) unphysiological intervention giving rise , among other possibilities , to carcinogenesis , ( 4 ) deleterious genetical selection operating on antigens , and ( 5 ) deleterious genetical selection operating on the immune response .
C0003320
antigens
C0301872
immune response