PSMD8 (Proteasome (prosome, macropain) 26S subunit, non-ATPase, 8), a significantly expressed gene in both cold- and heat-pattern RA patients, is one subunit of a protein-destroying apparatus that is involved in many essential cellular functions, such as the regulation of the cell cycle, cell differentiation, signal transduction pathways, antigen processing for appropriate immune responses, stress signaling, inflammatory responses, and apoptosis [46]. This evidence concerns the gene PSMD8 and rheumatoid arthritis.