After washing, slides were incubated with the appropriate secondary antibodies: fluorescence isothiocyanate (FITC) labelled anti‐rabbit antibody (1:200, Chemicon, Int. Inc., USA) and Cy3 labelled antimouse antibody (1:1000 Chemicon, Int. Inc., USA) for 1 hr at RT. Nuclei were stained with DAPI (1:1000) for 5 min. Finally, slides were mounted in fluorescent mounting medium Permafluor (Thermo Scientific, Wilmington, USA) and digital images were acquired using a Leica DM IRB fluorescence microscope and with Leica TCS SP8 confocal microscope. Nonspecific staining of cells was observed in control incubations in which the primary antibodies were omitted.