ESR1 and pancreatic neoplasm: To conditionally activate ROCK2:ER in Pdx1‐expressing KrasG12D/p53R172H pancreatic tumor cells (Appendix Figs S2 and S3), tamoxifen citrate or vehicle control was administered to RKPC cohorts for 9 weeks, starting at 10 weeks of age when KPC mice have typically progressed to the PanIN stage (Fig 1F) (Morton et al, 2010).