...we evaluated the effect of ZEN-3694 on the proliferation of ER+ breast cancer cell lines (Fig. 2). ZEN-3694 inhibited the proliferation of several ER+ cell lines at low micromolar concentrations and importantly had similar antiproliferative effects in wild type and CDK4/6i resistant cell lines, which indicates that ZEN-3694 can potentially alleviate the developed resistance to these agents...