This in vitro study exposed glioblastoma (CT2A), neuroblastoma (N2A), and non-tumor astrocyte (C8D1A) cell models to a 100 μT magnetic field across 20–100 Hz for 24–72 hours. The abstract reports decreased viability and proliferation in the tumor cell models within a frequency window centered at 50 Hz, while astrocyte viability increased at 20 and 40 Hz. The authors conclude that frequency is a key determinant of cell-type-specific responses consistent with a “biological window” model.