CERS4 and infection: The inhibition of p-JNK levels by transiently overexpressed CerS4 during infection was also observed when A549 cells were infected by pH1N1 at an MOI of 0.1 and 1.0 (Fig. 5C through E), where virus-induced increase of p-JNK was more evidently observed at an MOI of 1.0, presumably due to the higher MOI used for infection.