PYK2 and its closely related focal adhesion kinase (FAK) are key mediators of various mitogenic and migratory pathways. Prof. Sima Lev discovered PYK2 and showed that it is tightly regulated by intracellular calcium level and mediates mitogenic signals of diverse growth factors, hormones and neuropeptides. PYK2 is also activated by integrin clustering, localizes to focal adhesions (see below) and regulates the growth and metastasis of several tumors including breast cancer. Prof. Lev identified the key signaling pathways that are regulated by PYK2, and more recently demonstrated that PYK2 positively regulates Epithelial-mesenchymal transition (EMT) of breast cancer cells and that inhibition of PYK2 attenuates tumor growth in preclinical models. Currently, Prof. Lev investigates the role of PYK2 in crosstalk between tumor cells and the immune microenvironment.