These results reveal for the first time that BRCA1 haplo-insufficiency in iMSCs strongly affects the tumor microenvironment by promoting tumor angiogenesis, specifically through the release of angiogenic factors under hypoxia and the secretion of POSTN, which promotes angiogenesis through paracrine regulation of the adhesion and migration of endothelial cells. Here, BRCA1 is linked to neoplasm.