"**Motto**" Moduli space of Calabi-Yau varieties can be connected by using [Symplectic surgery theory][1]. Such surgery are very important for study of Hermitian–Yang–Mills metrics under conifold transitions A conifold transition is a surgery on a (real) six-dimensional manifold $X$ which replaces a three-sphere with trivial normal bundle by a two-sphere with trivial normal bundle, cutting out $S^3 × D^3$ and replacing it with $D^4 × S^2$. [Miles Reid][2] conjectured that the moduli space of Calabi-Yau spaces $\mathscr M_{CY}$ is connected after allowing the conifold transitions , i.e., both resolutions/contractions and deformations/degeneration. Is there any progress about this conjecture (what about in higher dimension), A reference or information is welcomed . See [some partial result][3] [1]: https://spiral.imperial.ac.uk/bitstream/10044/1/231/1/Symplectic%20conifold%20transitions.pdf [2]: https://arxiv.org/pdf/0904.4487.pdf [3]: http://link.springer.com/article/10.1007%2FBF01218081