E1BCJ2 (gene name: CFHR5, complement factor H related 5), E1BD43 (gene name: AOC3, protein name: amine oxidase involved in lymphocyte binding), F1MM86 (gene name: C6; protein name: complement component C6 involved in the regulation of complement cascade), F1N045 (gene name: C7; protein name: complement component C7), F2X047 (gene name: LYZ; protein name: lysozyme involved in hydrolysis signaling pathway), and Q9N2I2 (gene name: SERPINA5; protein name: plasma serine protease inhibitor) were differentially expressed in sera of infected buffaloes at all three time points after infection. The gene discussed is AOC3; the disease is infection.