TBX5 and posterior cortical atrophy: The present study aims to examine the role of FGFR1 expression and activation in acquired resistance to MET/VEGFR2 inhibition by cabozantinib in PCa, demonstrate whether an FGF/FGFR1 autocrine loop serves as a compensatory mechanism for cell survival, and determine the role of YAP and TBX5 in the expression of FGFR1.