CD4 and systemic lupus erythematosus: To examine whether after cleavage by metalloproteases, soluble CD95L had a chemoattractive effect on all T cells or was selective for distinct Th cell subsets, we next evaluated transmigration of undifferentiated (Th0) and differentiated (Th1 and Th17) CD4+ T cells with or without serum from SLE patients.