Landau levels offer a neat model system to study emergent quantum phases, owing to the dominating Coulomb interactions and tunable orbital wavefunctions. In atomically-thin transition metal dicalcogenide, the well-resolved and -controlled spin, valley and layer degree of freedom further enriches the physics that can be explored. In this talk, I’ll discuss a few examples in WSe2: first, a bilayer WSe2 allows selective carrier population of the individual layers; when the filling factor of the two layers is an integer number, it manifests as a natural platform for interlayer exciton condensate. Second, a large imbalance in the population of two (pseudo)spins gives rise to spin-dependent transport in partially filled Landau levels - the spin-minority carriers are much less mobile than the spin-majority carriers. We explain such behavior using a polaron picture.