TNFRSF9 and lung carcinoma: However, the percentage of CD137+ Tregs ranged from 1.9% to 15.2% in patients (mean, 6.06%) and from 1.2% to 9.1% (mean, 3.62%) in healthy donors; thus, the percentage of CD137+ Tregs was significantly increased in lung cancer patients compared to healthy controls (P=0.0015, Figure 3C).