Effects of 1,25(OH)₂D₃ on total TM and TF antigen in U937 cells. Dose-dependent effects of 1,25(OH)₂D₃ on TM (A) and TF (B) antigen expression in U937 cells. U937 cells were incubated with 1,25(OH)₂D₃ (0.1 nmol/L to 5 μmol/L) for 24 hours. These assays were repeated independently three times and the results are expressed as the mean ± SD (standard deviation).