SP1 and breast cancer: SP1 has been reported to accelerate tumor progression by regulating cell cycle‐related genes to accelerate tumor cell proliferation and facilitating the expression of vascular endothelial growth factors to promote angiogenesis.[20] Immunohistochemical staining of SP1 in primary lesions of breast cancer patients demonstrated that patients who developed lung metastasis later showed a higher level of SP1 staining (Figure S7J, Supporting Information).