ITGAL and leukemia: It was reported that the beta 2-integrin LFA-1 (CD11a/CD18) and the LFA-1/Mac-1 counter-receptor ICAM-1 are expressed on leukaemia (HMC-1 cells) and on normal mature human skin mast cells, which possibly play an important role during homing of immature mast cells as well as during the interaction of activated mast cells with other inflammatory cells [32].