BEIJING — Chinese researchers have identified 21 key proteins that can inhibit or encourage the growth of lung cancer cells, according to a recent study published in the international journal Cancer Letters.

Using genome-wide screening techniques, researchers from the Institute of Zoology under the Chinese Academy of Sciences tested 1,530 transcription factors (TFs), which are key proteins bound to DNA sequences that control the gene expression and decode information in the human genome.

They found that 11 TFs were tumor suppressors preventing the growth of lung cancer cells, while another 10 had the potential to cause lung cancer.

Further study showed that IRX5, one of the 10 dangerous TFs, was often discovered at high levels in lung cancer patients with tobacco smoke as the main cause. In experiments done on mice, researchers stopped lung cancer cells from growing by inhibiting IRX5.

Lung cancer is one of the most common cancers and the leading cause of cancer-related mortality worldwide.

In China, 730,000 new cases and 610,000 deaths from lung cancer are reported every year. Only 18 percent of lung cancer patients can live more than five years from the time of diagnosis.