After infection of MEFwt in the presence of nocodazole, ICP4 was not detected (Fig 3Bi), whereas in MEF-Impα1-/- (Fig 3Ci) and in MEF-Impα3-/- (Fig 3Di) there was some nuclear ICP4, although considerably less than in MEFwt or MEF-Impα4-/- (Fig 3Ei). This evidence concerns the gene IMPA1 and infection.