Minimal change nephropathy (MCN) has been associated with a wide variety of abnormalities in the immune response of affected individuals. Many of these may be a consequence of the renal lesion, rather than a cause thereof. This article reviews some of these immunological phenomena and concentrates in particular on the imbalance between type 1 and type 2 cytokine responses, suggesting that there are plausible mechanisms whereby a type 2 cytokine bias could directly or indirectly cause MCN.