GPER1 and neoplasm: The results showed that BBR could bind to GPER1 (Kd = 0.89 nM) and changed the secondary structure of GPER1 similar to E2 (Figure 3D,E), which proved that BBR promotes the GPER1 pathway as an agonist of GPER1, and this was consistent with the dependence of the anti-tumor effect of BBR on E2, shown in Figure 3F.