In agreement with this evidence, proteolysis of paxillin by calpain between the LD1 and LD2 motifs in HeLa cells generates a carboxy-terminal 55 KDa fragment, similar to delta paxillin, which functions as an antagonist of endogenous paxillin and may function to limit cancer cell invasion by preventing the assembly/disassembly of FAs and cell migration [120, 121]. The gene discussed is PXN; the disease is cancer.