For example, PCs in gliomas can promote DNA repair and induce resistance to temozolomide (TMZ) drugs through secreting CCL5 and binding to CCR5 expressed on glioblastoma multiforme (GBM) cells, conversely, silencing the CCL5-CCR5 signal can improve the efficacy of TMZ [299]. This evidence concerns the gene CCR5 and glioblastoma.