GPER1 and colorectal carcinoma: Intriguingly, when we again moved into an in vivo model of CRC, the use of the GPER antagonist G15 (at 50 μg/kg intraperitoneally thrice weekly) also significantly (P < 0.01) inhibited HCT116[sts] xenograft growth implanted into female nude mice (Fig. 4G).