Angiogenesis is essential for tumor growth and metastasis, driven by a balance of pro- and anti-angiogenic factors. Tumor cells often lack the endogenous anti-angiogenic molecule interferon beta (IFN β), leading to excessive angiogenesis. Therapies using IFN α or β can inhibit angiogenesis and tumor growth. Cancer metastasis is influenced by tumor-cell-host interactions, with metastatic potential determined by the "seed and soil" hypothesis, where tumor cells (seeds) must find compatible host environments (soil). Tumor angiogenesis is a key process in tumor progression, involving steps like basement membrane degradation, endothelial cell migration, and capillary formation. Pro-angiogenic factors include FGF, VEGF, and IL-8, while anti-angiogenic factors like IFN β inhibit angiogenesis. The tumor microenvironment regulates angiogenesis through factors like bFGF and IL-8. IFN β can suppress angiogenesis by down-regulating bFGF and other pro-angiogenic molecules. In cutaneous hemangiomas, IFN α accelerates regression by reducing pro-angiogenic molecules. IFN β has anti-angiogenic effects by inhibiting endothelial cell proliferation and migration, and by modulating angiogenic factors. IFN β gene therapy can inhibit tumor growth and metastasis in animal models. The balance between pro- and anti-angiogenic factors is crucial for controlling angiogenesis in tumors, and systemic IFN α or β therapy shows promise in treating various cancers.Angiogenesis is essential for tumor growth and metastasis, driven by a balance of pro- and anti-angiogenic factors. Tumor cells often lack the endogenous anti-angiogenic molecule interferon beta (IFN β), leading to excessive angiogenesis. Therapies using IFN α or β can inhibit angiogenesis and tumor growth. Cancer metastasis is influenced by tumor-cell-host interactions, with metastatic potential determined by the "seed and soil" hypothesis, where tumor cells (seeds) must find compatible host environments (soil). Tumor angiogenesis is a key process in tumor progression, involving steps like basement membrane degradation, endothelial cell migration, and capillary formation. Pro-angiogenic factors include FGF, VEGF, and IL-8, while anti-angiogenic factors like IFN β inhibit angiogenesis. The tumor microenvironment regulates angiogenesis through factors like bFGF and IL-8. IFN β can suppress angiogenesis by down-regulating bFGF and other pro-angiogenic molecules. In cutaneous hemangiomas, IFN α accelerates regression by reducing pro-angiogenic molecules. IFN β has anti-angiogenic effects by inhibiting endothelial cell proliferation and migration, and by modulating angiogenic factors. IFN β gene therapy can inhibit tumor growth and metastasis in animal models. The balance between pro- and anti-angiogenic factors is crucial for controlling angiogenesis in tumors, and systemic IFN α or β therapy shows promise in treating various cancers.