  We propose a relation between correlation functions in the 2d A_{N-1}
conformal Toda theories and the Nekrasov instanton partition functions in
certain conformal N=2 SU(N) 4d quiver gauge theories. Our proposal generalises
the recently uncovered relation between the Liouville theory and SU(2) quivers.
New features appear in the analysis that have no counterparts in the Liouville
case.
