Interestingly, we found an age independent increase in autophagy in the B cells of the lupus prone NZB/W F1 strain, with significantly more autophagy than the control B6 strain even at a young age, 4 weeks, before the onset of disease.19 NZB/W mice have a genetically determined defect in B cell activation, with excessive polyclonal IgM production from shortly after birth, and impaired tolerance induction.20, 21 The function of autophagy activation in these mice, as with the human SLE data, may represent an attempt by autoreactive B cells to survive deletion. This evidence concerns the gene CD40LG and systemic lupus erythematosus.