In this study, we evaluated the early (first 48 hours) serum levels of prolactin, cortisol, and interleukins and plasma levels of ACTH, eHSP90α, and eHSP72 and measured mean fluorescence intensity (MFI) of iHSP72 and iHSP90α in ICU patients with severe sepsis and septic shock (SS) or systemic inflammatory response syndrome (SIRS) compared to healthy control subjects (Η). The gene discussed is PRL; the disease is Sepsis.