We showed that IAV/WSN infection induced the conversion of PrPC into PrPSc in parental N2a cells, which express only endogenous mouse PrPC [24], indicating that overexpression of PrPC is dispensable for IAV/WSN infection to induce the conversion of PrPC into PrPSc. The gene discussed is PRNP; the disease is early-onset parkinsonism-intellectual disability syndrome.