Moreover, treatment with POP-Gel causes a decrease in HIF-1α and VEGF levels and inhibited the metastasis of the primary tumour to inguinal lymph nodes; additionally, after PDT treatment in orthotopic 4T1 tumour-bearing mice, the primary tumours growth was supressed, and the metastasis to the lung was reduced to only 3%. The gene discussed is HIF1A; the disease is neoplasm.