CD81 and glioblastoma: We found that, after 6 Gy irradiation, the percentage of G2/M-arrested population in the siCD81-transfected cells was lower than that in the siNC-transfected cells (8.1% vs. 21.3% in U251R cells; 9.68% vs. 17.68% in T98G cells) (Supplement Figure S2A,B), which further strengthens the deduction that CD81 contributes to HRR in overcoming IR-induced DNA damage in GBM cells.