  The extended QED with renormalizable interactions breaking the Lorentz and
CPT symmetry is considered and the phenomenological consequences of such a
symmetry breaking are illuminated in view of recent discussion of large scale
anisotropy of the Universe. Other physical effects in QED with CPT violation
are examined, in particular, mass splitting between electrons of different
helicities and decay of very high energetic electrons into lower energy
electrons and positrons.
