Aim To investigate the location and expression of tissue factor pathway inhibitor-2(TFPI-2) in U937 cell-derived foam cells.Methods Foam cell model was established by incubating the human monoblastic leukemia(U937) cells with oxidized low density lipoprotein(ox-LDL).Double immuofluorescence was used to detect the location of TFPI-2 protein.Human umbilical vein endothelial cells(hUVEC) were incubated with U937,the effects of the expression of TFPI-2 on U937 cell-derived foam cells were observed.The expression of TFPI-2 protein was examined by time-resolved fluoroimmunoassay(TRFIA).The expression of TFPI-2 mRNA was examined by reverse transcription-polymerase chain reaction(RT-PCR) and real-time PCR.Results TFPI-2 protein distributed mainly in the cytoplasm of U937 cells.U937 cells were incubated with ox-LDL,the mRNA and protein of TFPI-2 peaked at 6 hours,then the levels of TFPI-2 decreased in a time dependent manner.After being added hUVEC,the expression of TFPI-2 in U937 increased.Conclusion Ox-LDL reduced the expression of TFPI-2 in U937 cells,incubated with hUVEC can modify the inhibitive effect.