Surprisingly, Ccr1, Ccr3 or Ccr5 mRNA levels were nearly undetectable in M-GBM cells (Supplementary Figure 6), prompting us to investigate non-conventional CCL5 receptors (GPR75, CXCR4 and CD44) as potential binding partners [23, 24]. The gene discussed is GPR75; the disease is glioblastoma.