Abstract: For quantum cohomology of a Fano manifold X, Gamma conjectures try to describe the asymptotic behavior of Dubrovin connection in terms of derived category of coherent sheaves on X, via the Gamma-integral structure of the quantum cohomology. In particular, Gamma conjecture I expects that the structure sheaf corresponds to a flat section with the smallest asymptotics. Recently, we discovered that certain toric Fano manifolds do not satisfy this conjecture. In this talk, we will report our results on these counter-examples, and propose modifications for Gamma conjecture I. This talk is self-contained, and is based on joint work with S. Galkin, J. Hu, H. Iritani, C. Li and Z. Su.