Expression of α7 nicotinic acetylcholine receptor protein in non-SCLC cell lines and normal SAE cells as assessed by western blot analysis. Protein was isolated with the ReadyPrep protein extraction kit (signal) (Biorad). Nitrocellulose membranes were incubated with the rabbit polyclonal antibody to the alpha 7 nicotinic acetylcholine receptor (Abcam). 1) SAEC; 2) A549; 3) NCI-727; 4) NCI-H226; 5) NCI-H520; 6) NCI-H2170; 7) NCI-H322. The arrow indicates the 56 kDa band (expected size). Only SAEC, A549 and NCI-H226 express protein for alpha 7 nicotinic acetylcholine receptor.