Immunohistochemical localization of wild-type and mutant FVII molecules in stably transfected CHO cells. FVIIwt (A, B) and FVIICys ⁹⁷ (C) were mostly localized in the perinuclear area, whereas FVIIArg¹⁰⁰ (D) was present diffusely throughout the cytoplasm without perinuclear enhancement. Untransfected CHO cells did not react with either the anti-FVII Mab or the fluorescent second antibody indicating that the observed labeling was specific for FVII (data not shown).