The asymmetry in matter production confirms grand unified theories.

Evidence

Thus our very existence could be regarded as a confirmation of grand unified theories, though a qualitative one only; the uncertainties are such that one cannot predict the numbers of quarks that will be left after the annihilation, or even whether it would be quarks or antiquarks that would remain. — Hawking, Stephen, A Brief History of Time, 143

Categorization

• corroborated: 2 independent passages support this claim — Hawking, Stephen, A Brief History of Time, 143