Each eukaryotic cell of multicellular organisms must be able to maintain its integrity by sensing
both external and internal stimuli. The primary goal of the generated response mechanism is to
drive back the system to the former or to a new homeostatic state. Moreover, the response has to
provide an accurate survival-or-death decision to avoid any “misunderstanding” and its unwanted
consequences. New data revealed that a systems-level crosstalk of molecular networks has an es-
sential role in achieving the correct characteristic of the response. Although many molecular
components of these processes already have been revealed, several elements and regulatory con-
nections of crosstalk are still missing. These “gaps” of the complex control networks make hardly
impossible to present comprehensive models. Therefore we approach the questions from a sys-
tems biology aspect by combining the experimental results with the special technique of mathe-
matical modelling. In this short report we discuss some novel and preliminary data gained by this
approach on the crosstalk between life and death decisions under cellular stress, to get a systems
biological view of these networks.