ITGAX and systemic lupus erythematosus: Further, by exploring the expression of CD11c and CXCR5 on B cells and B cell subsets we found a substantial decrease in the frequency of cells positive for CXCR5, in particular but not only in the DN B cell subset in which most impressively the CD11c-CXCR5- (DN3) subtype was highly increased and associated with SLE disease activity.