C3 and Dowling-Degos disease 1: The association of properdin-dependent C3NeFs with C3GN and terminal complement pathway activation in vivo is consistent with recent findings that in most (67%) C3GN patients, C3NeFs target both the C3 and C5 convertases (28), and that circulating markers of terminal pathway activity are altered more in C3GN than in DDD (46).