Verification of the candidate biomarkers’ expression by Western blotting. Membrane-associated protein lysates were resolved with sodium dodecyl sulfate polyacrylamide gel electrophoresis, and blots were incubated with an antibody against DPYL2, phospho-DPYL2 (Thr514/Ser518), GNAQ, RSSA, RUVB1, STMN1, or phospho-STMN1 (Ser16). Expression levels were normalized to actin. Overexpression of DPYL2, GNAQ, and STMN1 was observed in SCLC compared with immortalized normal bronchial epithelial (normal) and NSCLC cell lines, while RSSA and RUVB1 expression was similar in all the cell lines. Increased phosphorylation of DPYL2 and STMN1 was also observed in SCLC compared with normal and NSCLC cell lines, suggesting an activation of DPYL2 and STMN1 in SCLC. DPYL2, dihydropyrimidinase-related protein 2; GNAQ, guanine nucleotide binding protein alpha-q; NSCLC, non small-cell lung cancer; RSSA, laminin receptor 1; RUVB1, pontin; SCLC, small-cell lung cancer; STMN1, stathmin 1.