GPER1 and cancer: In the clinic, there are several lines of evidence suggesting that LNS8801 activity is linked to GPER signaling: (i) There are no signs of toxicity that would be characteristic of a microtubule inhibitor, even at doses and exposures above those required for clinical benefit (40); (ii) Progression-free survival across cancer types is highly correlated with expression of a functional/consensus version of GPER in patients (42); and (iii) A systemic, target engagement biomarker is highly correlated with progression free in patients across indications.