SDHAF2 and lung cancer: Most importantly, the SDH5 expression levels in plasma and tumors were positively correlated (rho=0.894, P<0.001), and lung cancer patients with lower expression of SDH5 had longer PFS (average median PFS 30.0 versus 15.0 months, P<0.001) and OS (average median OS 38.0 versus 25.0 months, P<0.001) after radiation.