ROCHESTER, Minn., Sept. 19 (UPI) -- A specific protein pair may be a successful prognostic -- predictor -- biomarker for identifying smoking-related lung cancers, U.S. researchers say.

Senior author George Vasmatzis, a Mayo Clinic molecular medicine researcher, and colleagues said the protein -- ASCL1 -- was associated with increased expression of the RET oncogene, a particular cancer-causing gene called RET.

"This is exciting because we've found what we believe to be a 'drugable target' here," Vasmatzis said in a statement. "It's a clear biomarker for aggressive adenocarcinomas of the lung -- the most common type of lung cancer in lifelong non-smokers. These are the fast-growing cancer cells found in smokers' lungs."

The study, published online in the journal Oncogene, found when researchers blocked the ASCL1 protein in lung cancer cell lines expressing both genes, the level of RET decreased and tumor growth slowed.

The findings suggested this mechanism might be a promising target for potential drugs and a strong candidate for clinical trials, Vasmatzis said.