CCL5 and central nervous system cancer: We found that high levels of CCL5 produced by pericytes correlated with short progression-free survival (PFS) and rapid tumor recurrence after TMZ treatment, whereas tumors with low levels of CCL5 correlated with longer PFS and slower tumor recurrence after TMZ treatment (Fig. 7a–d), suggesting that CCL5 could effectively predict TMZ efficacy in gliomas.