Fields of particular interest include first, a further elucidation of the ion–water disbalance upon excessive neutrophil activation, second, an in-depth evaluation of physiological parameters, including intracellular pH and cellular size of neutrophils as a diagnostic and/or prognostic marker of immune dysfunction, and third, a meaningful translation to the bedside by modulating ion–water based alterations, for example, by pharmacological targeting of perpetrator ion transport proteins, such as NHE1, during sepsis. The gene discussed is SLC9A1; the disease is immune system disorder.