Cytokine regulation of lymphocyte survival may play an important role in the control of the cell cycle during the immune response both in health and disease. Expression of the Bcl2 gene promotes cell survival by countering apoptosis stimuli. The p53 protein has been implicated in the control of the cell cycle, in the synthesis and repair of DNA and in programmed cell death. TH1 and TH2 cytokines exert a mutual cross-regulation on the precursors of TH1- or TH2-type effector cells which are important mediators in directing the immune system towards the appropriate response. TH1 and TH2 cytokines have also been implicated in the modulation of the expression of cell cycle regulator genes. Therefore, the study of the relationships between TH1 and TH2 cytokines and Bcl2 and p53 molecules in healthy subjects could lead to a better understanding of the physiological regulation of the immune response and identify markers for prognostic and diagnostic indices and biotherapeutic treatment. We determined the serum levels of cytokines (IL2, IFN gamma, IL4, IL10, IL5, IL6, IL1 beta, TNF alpha, IL8), soluble receptors (sIL2R, sIL6R), Bcl2-protein and p53-antibody in a group of healthy subjects. Multivariate statistical analyses were used to study the cytokine network relationships with Bcl2-protein and p53-antibody, as they allow a simultaneous evaluation of all variables which reflects the physiological situation. Our overall results suggest that relationships exist between TH1 and TH2 cytokines and the Bcl2-protein and p53-antibody in physiological conditions. This information could now be used in experimental studies to create diagnostic and prognostic indices for the monitoring of health and disease.