Does endogenously expressed myc make background in detection of myc-tagged prote - immunofluorescence (Nov/25/2007 )

Does endogenously expressed myc make background in detection of myc-tagged protein by immunofluorescence?
In what types of cell lines can myc tag be used for labelling proteins?
Is vero ok?
Any reply will be appreciated!

myc antigen does not create huge problems in cell culture but for invivo immunofluorescence, it does generate background.