Effect of D865 > G mutation on NIK-induced p100 processing and serine phosphorylation. (A-B) HEK293 cells were co-transfected with expression vectors encoding wild-type (WT) or D865 > G mutant NFKB2 together with varying amounts of MAP3K14 expression vector encoding NIK. (B) Summary of relative expression of p100 and p52 determined as determined in (A). Results were normalized to the ratio in the absence of NIK. (C-D) Phosphorylation of serines 867 and 870 in response to increasing dose of NIK. (D) Summary of phospho-NFKB2 as determined in (C). TATA box was used as a loading control. (E) p100 processing in response to CD40L in dendritic cells generated in vitro from PBMCs from I.1 or a healthy control.