Mice lacking the A1 adenosine receptor (A1 AR-deficient) and their wild-type littermate counterparts displayed distinct responses when injected with Gl261 glioblastoma tumor cells and subsequently treated with adenosine along with an A1 AR agonist, N6-cyclopentyladenosine (CPA), with CPA resulting in a notable reduction in tumor size. Here, ADORA1 is linked to neoplasm.