The paper by Wang et al. investigates the topological properties and quantum transport of Cd$_3$As$_2$, a well-known semiconductor with high carrier mobility. Using first-principles calculations, the authors confirm that Cd$_3$As$_2$ is a symmetry-protected topological semimetal with a single pair of three-dimensional (3D) Dirac points in its bulk and non-trivial Fermi arcs on its surfaces. The material can transition into a topological insulator, a Weyl semimetal, or a quantum spin Hall (QSH) insulator by symmetry breaking or reducing dimensionality, respectively. The 3D Dirac cones in Cd$_3$As$_2$ are expected to support significant linear quantum magnetoresistance up to room temperature. The study also discusses the crystal structure and methodology used for the calculations, including the modified second-order 8-band Kane model and the tight-binding model for surface states. The findings highlight the potential of Cd$_3$As$_2$ as a promising candidate for future transport studies and the exploration of topological phases.The paper by Wang et al. investigates the topological properties and quantum transport of Cd$_3$As$_2$, a well-known semiconductor with high carrier mobility. Using first-principles calculations, the authors confirm that Cd$_3$As$_2$ is a symmetry-protected topological semimetal with a single pair of three-dimensional (3D) Dirac points in its bulk and non-trivial Fermi arcs on its surfaces. The material can transition into a topological insulator, a Weyl semimetal, or a quantum spin Hall (QSH) insulator by symmetry breaking or reducing dimensionality, respectively. The 3D Dirac cones in Cd$_3$As$_2$ are expected to support significant linear quantum magnetoresistance up to room temperature. The study also discusses the crystal structure and methodology used for the calculations, including the modified second-order 8-band Kane model and the tight-binding model for surface states. The findings highlight the potential of Cd$_3$As$_2$ as a promising candidate for future transport studies and the exploration of topological phases.