In this work, we aim at defining FAK and PYK2 expression in CLL cells and exploring the effect of defactinib administration to CLL, both in vitro (2D and 3D culture) and in vivo, to understand how leukaemic cells could exploit mechano‐transduction pathways like FAs recruitment via FAK and PYK2 activation, to sustain their development, progression and resistance to therapy. Here, PTK2 is linked to B-cell chronic lymphocytic leukemia.