In the regulation of Th cell differentiation, inosine exerts bidirectional regulation on Th1 differentiation through the adenosine A2A receptor (A2AR), and its effects are environment-dependent: In the presence of exogenous IFN-γ and IL-12 secreted by dendritic cells, guanosine promotes Th1 differentiation by binding to the A2AR on the surface of T cells, and significantly enhances the anticancer activity of Th1 cells in various tumors such as melanoma, bladder cancer, and CRC (He et al., 2017). This evidence concerns the gene ADORA2A and urinary bladder cancer.