  Gauge-Yukawa Unification (GYU) yields a functional relation among the gauge
and Yukawa couplings, and it may follow from the usual Grand Unification if it
is supplemented with some additional principles. Postulating the principles of
finiteness and reduction of couplings, we have achieved Gauge-Yukawa
Unification in various supersymmetric unified models leading, among other
things, to interesting predictions on the top quark mass.
