Western blot analysis of NSCLC patients’ pleural effusions and sera for Abs against L514S, L552S, and NY-ESO-1. Three pleural effusions (A) and three sera (B) were selected by ELISA using His-tag recombinant proteins L514S (solid arrow), L552S (dotted arrow), and NY-ESO-1 (partially dotted arrow). These were added to a nitrocellulose membrane on which the three proteins were blotted. After washing with 0.05% Tween/PBS, the membranes were developed by HRP-conjugated antihuman IgG and chemiluminescence substrate. The molecular weights of the L514S, L552S, and NY-ESO-1 His-tag proteins were determined to be 16 kDa, 18 kDa, and 18 kDa, respectively, by silver staining (left).