DRD1 and glioblastoma: In the context of neurotransmitter-mediated regulation of cancer phenotypes, dopamine receptors DRD1 and DRD5 (D1-like subfamily: coupled to Gαs or Gαlf proteins), whose transcripts were expressed in the GBM patient-derived cells evaluated here, and also DRD2 and DRD3 (D2-like subfamily: coupled to Gαi/o) were among the possible proteins interacting with A5 (D1-like subfamily only), C1 or APO.