Introduction HNF1B is a tissue-specific transcription factor, which plays a crucial role in the embryological development of a number of organs, especially kidneys, gastrointestinal system, pancreas and billiary system. While the significance of HNF1B in the development of urinary tract malformations has already been well described, its role in the pathogenesis of solid tumors has not yet been elucidated. Based on the current data it seems that depending on the type of individual tumor HNF1B can either act as an oncogene or a tumor suppressor. However, the precise mechanism of how it exerts its influence is still unclear. Aims: The thesis focuses on expanding the knowledge of the significance of HNF1B changes in selected solid tumors and non-neoplastic lesions. The individual goals include: 1) determining the role which HNF1B plays in the pathogenesis of these lesions, 2) evaluating the significance of HNF1B for differential diagnosis, 3) analysis of the prognostic and predictive meaning of HNF1B, 4) mutation analysis of the HNF1B gene in all the tumor and non-tumor tissues with the aim to identify novel pathogenic mutations, 5) methylation analysis of the HNF1B promoter. Material and methods: Immunohistochemical examination with the antibody against HNF1B was performed on 516 samples of tumor and..
