Subsequently, GBMTREM2−KD and paired GBM-NC cells were exposed to radiotherapy at the dose of 2 Gy which was commonly used in clinical practice, and we found that the expression of PARP1 in GBMTREM2−KD cells was significantly decreased, while the expression of cleaved PARP1 and γ-H2AX were significantly increased (Fig. 2F), suggesting radiotherapy was more likely to cause DNA damage in GBMTREM2−KD cells than GBM-NC cells. Here, PARP1 is linked to glioblastoma.