FACS analysis of TIE (dotted lines) and TEK (broken lines) expression. Anti-TIE and TEK MoAbs reacted with each indicator cell, BaF/TIE (A) and BaF/TEK cells (B), respectively, but not with BaF/Vector cells (C). The reactivity of anti-TIE and TEK MoAbs was blocked by an excess molar of TIE-FLAG and TEK-FLAG proteins (thick lines). Both anti-TIE and anti-TEK MoAbs reacted with DA-1 cells (D). Thin lines denote negative control cells stained with FITC-conjugated streptavidin alone.