APP and infection: In relation to the MHC class I APP pathway, in the orange-spotted grouper, the expression of MHC class I genotype EcMHC-I A*01, was induced by infection with red-grouper nervous necrosis virus (RGNNV) or Singapore grouper iridovirus (SGIV) in liver and spleen tissues and, in turn, overexpression of EcMHC-I A*01 reduced expression of viral genes [47].