The term 'Immunculus' has been proposed for designation of the global system (network) of constitutively expressed natural autoantibodies (na-Ab) interacting specifically with different extracellular, membrane, cytoplasmic, and nuclear self-antigens. In healthy persons the repertoires of such na-Ab are surprisingly constant and characterized by minimal individual quantitative variations. On the other hand, abnormal metabolic deviations, which precede or accompany different diseases show easily detectable prominent changes, rather quantitative than qualitative, in the network of na-Ab in the patient's sera (Immunculus distortions). This phenomenon can be used for 'mapping' the state of physiological norm in terms of the millennia of na-Ab repertoires, and for the elaboration of methods for an early (pre-clinical) detection of potentially pathogenic metabolic changes. Can the individual features of the general network of constitutively expressed na-Ab reflect the functional state of the body and be used for 'mapping' of normal and pathological functional state? Can the changes in production of some biologically active na-Ab not only reflect the state of the body, but also be used for partial compensation of functional deficiency of certain molecular systems? These and related questions are discussed in this article. The research project 'Immunculus' is proposed for international cooperative investigations.