NOS2 and Carcinoma, Lewis Lung: To determine the endothelial specificity of the effects described above, primary lung murine endothelial cells (mEC), human umbilical vein endothelial cells (hUVEC), murine embryonic fibroblasts (mEF), and Lewis lung carcinoma cells (LLC) were treated with the iNOS inhibitor 1400W (Figure 4A).