Abstract: Since Floer's work in 1988, various Floer homologies have been constructed for closed 3-manifolds, knots, and sutured manifolds. In 2008, Kronheimer-Mrowka proposed a conjecture about isomorphisms among Floer homologies. In this talk, I will introduce an approach to proving the isomorphisms and mention some partial results, based on combinatorial version of Floer homology. This work is joint with Baldwin, Li, and Sivek.