MAPT and viral infectious disease: 57–59 For example, the protein products of DDX5, U2AF2 and ILF3 play important roles in Tau protein splicing and biology.59–61 A major environmental factor that results in loss of A-to-I editing is viral infection, including both acute and chronic infection in diverse tissues and by infection with either single stranded or dsRNA viruses.25,26,62 Whether this may imply presence or absence of viral infection or differences in the host response to infection is unknown.