In fact, lower expression and production of pro-inflammatory cytokines were found in LPS-stimulated PBMCs from individuals with higher cortisol levels, suggesting reduced ability to respond to bacterial infections and increased vulnerability among workers to infectious diseases, which is in accordance with previous studies showing that long-term exposure to cortisol may impair the response of the immune system by a downregulation of hormonal receptors [80]. This evidence concerns the gene NR4A1 and infectious disease.