A, schematic representation of MAPK-signaling pathway and the sites for inhibitor action. B, model of the luciferase-reporter system. C and D, effects of genistein on HIF-1 activity. B1 cells were exposed to various doses of genistein, a tyrosine kinase inhibitor, and cultured in normoxia (C) or in a hypoxic work station with 2% O2 (D) for 8 h. E and F, effects of PDx on HIF-1 activity. B1 cells were exposed to various doses of PDx, MAPK inhibitor, under normoxic or hypoxic conditions (2% O2) for 8 h. RLU, relative light units.