This in vitro study compared proteomic profiles of PBMCs from three human donors after 24-hour exposure to a 50 Hz, 1 mT extremely low-frequency magnetic field versus unexposed cells. The abstract reports broad protein expression changes, including upregulation of proteins associated with metabolic processes and downregulation of proteins linked to T cell costimulation/activation and immune processes. No effects were observed on cell proliferation, viability, or cell cycle progression. The authors interpret the proteomic shifts as metabolic reprogramming with potential implications for immune regulation.