HEK293 cells and HEK-mKL cells were pre-treated with 5 uM AG1478 for 30 minutes, followed by 8 h 500 ng/ml rhHBEGF or rhFGF23; the control cells were treated with 10 ul of DMSO. In HEK293 cells, EGR1 (A) and CYP24A1 (B) mRNAs were induced with rhHBEGF treatment; this increase was blocked by AG1478 and there were no changes in CYP27B1 (C). In HEK-mKL cells, the increased EGR1 was modestly suppressed by AG1478 (D), however CYP24A1 expression remained elevated (E); there were no changes in CYP27B1 (F) (# P<0.05, ##P<0.01 versus HBEGF or FGF23 group. *P<0.05, **P<0.01 versus control group. N=3. ‘Ctrl’, control).