Updated publication reference for PubMed record(s): 32302149. Microglial cell activation has been linked to many neurodegenerative diseases. Upon stimulation by lipopolysaccharide (LPS), a number of proteins involved in inflammatory and oxidative pathways are activated. Production of nitric oxide has been regarded as a signature marker of inflammatory responses. Our recent studies demonstrated the effects of docosahexaenoic acid (DHA) to inhibit the LPS-induced inflammatory responses in BV-2 microglial cells. DHA also can upregulate the anti-oxidative pathway involving nuclear factor erythroid 2-Like 2 (Nrf2) and synthesis of heme oxygenase-1 (HO-1), a potent anti-oxidative enzyme. In order to further understand the proteins involved, this study used a label-free quantitative proteomics approach to examine effects of DHA and LPS on proteins and signaling pathways in microglial cells.