HIF1A and breast cancer: In this study, we demonstrated for the first time that compound 1, a pregnane alkaloid derivative, bonds directly with HSP90α, leading to the downregulation of HIF-1α and its downstream signaling pathways and inhibition of breast cancer matastasis and angiogenesis in vitro and in vivo, Furthermore, treatment with 1 (40 mg/kg) demonstrated more efficacy in antimetastasis and antiangiogenesis than Sorafenib (50 mg/kg).