PTK2 and mantle cell lymphoma: Moreover, in vitro based studies have shown that a Hedgehog (Hh) inhibitor, LDE225, suppresses both migration and retention of the MCL cells in the BM, and this effect is shown to be mediated by inhibiting FAK signaling in MCL cells and suppressing IL-6, SDF-1, and VCAM-1 expression by BM stromal cells.