ITGB2 and systemic lupus erythematosus: ITGAM encodes the CD11b chain of the Mac-1 integrin complex (alphaMbeta2; CD11b/CD18; complement receptor-3) and in the context of SLE, ITGAM expression may be protective through mediation of phagocytosis of iC3b-opsonised apoptotic material, inhibition of T cell activation, restriction of toll-like receptor signaling and inhibition of Th17 responses19.