As a major cytokine in many viral infections, IFNγ upregulates the expression of MHC class I [14] and three immunoproteasome subunits β1i (LMP2), β2i (MECL-1), and β5i (LMP7), which replace their constitutive counterparts, β1, β2, and β5 [15], [16], and consequently increases the activity of the MHC I antigen presentation pathway [17]. The gene discussed is IFNG; the disease is viral infectious disease.