ADORA2A and columnar cell hyperplasia of the breast: Compared with the GFAP and YKL-40 levels in the CCH group, the expression in the SCH58261 group were significantly higher, whereas those in the CGS21680 group were significantly lower, indicating that the activation of ADORA2A could inhibit the activation of astrocytes and reduce the expression of YKL-40 (Figures 2B–D).