PKP2 and cancer: G2 and S phase-expressed 1(GTSE1) (46), plakophilin2 (PKP2) (47), ephrin type-A receptor 2 (EphA2) (48, 49), and cancer-derived IgG (cancer-IgG) (50) can participate in NHEJ pathway, leading to radioresistance in NSCLC.