ESR1 and breast cancer: LGK-974 (PORCN inhibitor) rescued enhanced proliferation of INPP4B-overexpressing PIK3CA-mutant ER+ human breast cancer cells [25].Pyrvinium (CK1α inhibitor) reduced viability and 3D spheroid growth of INPP4B-overexpressing PIK3CA-mutant ER+ human breast cancer cells [102].