Bose originated (with Marletto and Vedral) the Bose-Marletto-Vedral (BMV) proposal to witness whether gravity is fundamentally quantum, by testing for gravitationally-induced entanglement between two spatially superposed masses using matter-wave (Stern-Gerlach) interferometry -- an idea he co-developed with quantum-sensing experimentalists including Andrew Geraci (Northwestern) and Peter Barker (UCL). He continues to develop the theory of these quantum-gravity-induced entanglement of masses (QGEM) tests, including decoherence mitigation and multi-qubit witnessing schemes, positioning nanocrystal/levitated-mass interferometry as a route to laboratory tests of quantum gravity.