The plethora of cellular processes involved in tumor formation, their complexity and fast evolution represent the clinical puzzle of cancer disease. My background in Molecular Biology of cancer and fibrotic diseases has shaped my scientific interests on the fascinating role of the microenvironment on tumor growth and the crosstalk among the stromal and tumor components. To elucidate the mechanisms of stroma contribution to tumor growth I am studying the molecular transcriptome of tumor and tumor-supporting cells in patient-derived xenograft models and determine the reciprocal oncogenic signals during tumor-stroma interactions and their prognostic value in clinical specimens. Moreover, therapy response and acquisition of therapy resistance has been associated with particular stem-like cell populations. The presence of a (stem) cell hierarchy within a tumor and their potential different roles require further understanding, for which in vivo xenograft models are essential. To elucidate this, we aim to characterise the tumor initiating potential and molecular (genomic and transcriptomic) signatures of cancer stem cell populations that drive Castration Resistant Prostate Cancer and metastasis based on stem cell marker expression. Furthermore, drug response and resistance are assessed in patient derived ex vivo, xenograft and organoid culture models.