This indicates that Nr4a1-microglia-mediated synapse elimination may be regulated by neuronal activity in the SLE setting, such that microglia preferentially engulf synapses of ‘weaker’ neurons, as similar rules reported in the developing brain38 and microglia mediate forgetting in the adult brain.35 Lupus mice with restored NR4A1 expression in neurons were largely protected from synapse loss and microcircuit dysfunction. Here, NR4A1 is linked to systemic lupus erythematosus.