Western blotting validation of proteins identified as differentially expressed in the 2-DE/MS analysis. Protein lysates from HCC827, H3122, A549 and H1437 cells without treatment or inhibited with 17-AAG, IPI-504, STA-9090, AUY-922 VER-155008 + 17AAG and VER-155008 as well as the genetic silencing of HSP90 were immunoblotted. Expression study of (A) eIF3i and (B) CS after HSP90 inhibition as well as its loading control are shown. eIF3i = eukaryotic translation initiation factor 3 subunit I, CS = citrate synthase. For Western blots, a representative image is shown. Densitometry analysis may be found in Figure S8.