Cancer-associated fibroblasts (CAFs) constitute the most prevalent, yet heterogeneous, component of the tumor stroma. CAF plasticity results in a spectrum of functional states; including an extracellular matrix producing and contractile myofibroblast state (myCAF) and enables adaptation to stress induced by cancer targeted therapies (TT). MEK TT is a standard-of-care treatment in recurrent low-grade serous ovarian carcinoma, a tumor type characterized by high frequency of activating mutations in the MEK pathway. The impact of MEK TT on CAF  state and its reciprocal effect on cancer progression and treatment efficacy will be investigated using 3D cell culture and animal models and also validated in patient settings. Our expertise in CAF biology, 3D spheroid and mouse models, along with availability of clinical specimens will allow to study our unpublished data in further detail.