EIF2AK3 and viral infectious disease: In the first set of experiments we found that viral infection of cortical primary neurons (DIV17 and DIV21) with a RasGRF2 shRNA1 had no effect on basal pERK levels in accord with our previous observation (Bido et al., 2015), but it reduced the 4-AP/bicuculline induced increase of pERK in immunoblot experiments in mature cultures (Figure S2D).