We briefly recall the original statement of the Connes Embedding Problem(CEP), which was in terms of traces, and Kirchberg's equivalent problem about tensor norms on group algebras. We then introduce synchronous games, synchronous correlations and their connections with traces. This leads to the concept of the fundamental orthogonality relations(FOR) of a synchronous game. From this viewpoint, MIP*=RE gives a negative answer to the CEP by showing the existence of a FOR that can be realized in a tracial C*-algebra, but not in the algebra considered by Connes.