The most significant, predicted activated upstream regulators in OS-2 (worse prognosis), relative to OS-1 tumor xenografts, were CEBPB and NFKB1 (P-value 5.54E–10 and 3.94E–09, respectively), whereas the most significant predicted inhibited upstream regulator was MEF2C (P-value 2.54E–23) (Table S3). The gene discussed is MEF2C; the disease is neoplasm.