IL4 and systemic lupus erythematosus: IL-15 increased IL-4 production of iNKT cells from SLE patients (62.7±5.7% vs. 49.4±5.8%, p = 0.04) but had little effect on controls (72.5±6.3% vs. 70.6±5.8%, p = 0.311) (Fig 6C).