2D Weyl semimetals are spin-polarized analogues of graphene that promise access to topological properties of Weyl fermions in (2+1)-dim spacetime. In 2024, an intrinsic 2D Weyl semimetal with spin-polarized Weyl cones and topological Fermi string edge states was discovered in epitaxial monolayer bismuthene by a team from University of Missouri, National Cheng Kung University, and Oak Ridge National Laboratory.