  We review the concept of chirality and charge for particles and
antiparticles. We point out that the commonly accepted equivalence of particles
and antiparticles - with difference only in the opposite signs of their
charges, which follows from the CPT invariance - is valid only for free
non-chiral particles. We show that with the weak interaction turned on the
equivalence of particles and antiparticles is violated. We also discuss that
within the Standard Model even free neutrinos are exceptions, they can be
produced only in chiral states. We conclude that in spite of a long history of
antiparticles, interesting theoretical and experimental challenges remain in
their complete understanding.
