K8/K18 IF modulation of ASMase localization and activity. (A) Immunofluorescence confocal imaging of the ASMase localization in WT and K8-null hepatocytes, revealing no major differences. (B) XZ views of ASMase immunofluorescence images with or without a 2-h treatment with cisplatin (Cis; 5 µg/ml) in WT and K8-null hepatocytes. In the absence of cisplatin, a slight decrease in ASMase localization is seen at the surface of hepatocytes lacking K8/K18 IFs, whereas an increased localization is observed at the surface of both cell types, following the cisplatin treatment. (C) ASMase activity assessments in WT and K8-null hepatocytes with or without a 2-h treatment with cisplatin (Cis; 5 µg/ml) or PMA (100 nM), showing a decrease in ASMase activity in hepatocytes lacking K8/K18 IFs, under either inhibitory conditions (C: untreated control). Results are mean±s.e.m. **P<0.01; ***P<0.005 (t-test).