Significant decrease was observed in the expression level of complex IV comprised of immunoglobulin super family member 8 (IGSF8) and microsomal glutathione S transferase (MGST1) along with complex XIII comprised syntaxin-1A (STX1A) and tubulin polymerization promoting protein (TPPP) in AD brain as compared to control samples. The gene discussed is TPPP; the disease is Alzheimer disease.