ITGAL and B-cell chronic lymphocytic leukemia: Increased expression of integrins including LFA-1 and VLA-4 on CLL cells among patients with trisomy 12 has also been reported by others and the increase has been associated with up-regulation of molecules regulating integrin inside-out signaling such as RAP1B and RAPL and with enhanced ligand (ICAM-1, VCAM-1) binding and migration in vitro (227, 228).