Bosma A et al. reported that normalization of CD1d expression on newly repopulated CD19+CD24hiCD38hi B cells corresponded to normalization of the invariant natural killer T (iNKT) cell number and function in SLE patients treated with rituximab, suggesting that Breg cells are critical in maintaining invariant natural killer (iNKT) cell homeostasis in humans27,28. The gene discussed is CD1D; the disease is systemic lupus erythematosus.