PEMF affected gene expression in MG-63 osteoblastlike cells (Fig. 1) . The genes differentially expressed in cells treated with PEMFs were either upregulated (268 genes) ( Table 1) or downregulated (277 genes) ( Table 2) . PEMF induced osteoblast proliferation and differentiation and regulated genes involved in bone formation in the direction of an enhancement of osteogenesis (Tables 3, 4 ).