I will talk about recent developments on simplicial maps of complexes of curves on both orientable and nonorientable surfaces. I will also talk about joint work with Prof. Luis Paris. We prove that on a compact, connected, nonorientable surface of genus at least 5, any superinjective simplicial map from the two-sided curve complex to itself is induced by a homeomorphism that is unique up to isotopy. As an application we give the classification of injective homomorphisms from finite index subgroups of the mapping class group to the whole group.