Letra Vilela Ribeiro, Ricardo José2023-05-292023-05-292022-05http://hdl.handle.net/10362/153285The STAT family of transcription factors plays key roles in the physiology of the immune system and during development. Among them, STAT3 is particularly relevant, as its deletion leads to early embryonic lethality. STAT3 is stimulated by a wide spectrum of cytokines and extracellular factors, regulating the transcription of genes related with survival/ apoptosis, proliferation and differentiation. STAT3 is overactivated in 70% of solid tumors, and activating mutations are related to cancer and some benign hyperproliferative disorders, such as Inflammatory Hepatocellular Adenome. STAT3 is considered an interesting target for cancer treatment, as it is also partially responsible for radio- and chemo resistance, and various direct or indirect inhibitors have been proposed as possible therapies.engSTATmolecular toolsdoctoral thesis101736860