Cell surface expression of HVEM is reduced on FL B cells with TNFRSF14 aberrations but expression of other molecules involved in antigen presentation is maintained. (A) Cell surface expression of HVEM (filled histograms) and isotype controls (open histograms) on FL B cells. Representative data are shown from patients with TNFRSF14 WT (left panel), single TNFRSF14 aberrations (middle panel), and dual TNFRSF14 aberrations (right panel). (B) Mean (± standard deviation) frequencies of HVEM⁺ cells, expressed as a percentage of FL B cells, for WT (n = 5), single aberration (n = 3), and dual TNFRSF14 aberration cases (n = 5). P value is for 2-tailed unpaired Student t test. (C) Surface expression of molecules involved in antigen presentation on FL B cells shown pre- and postactivation. The mean values are shown for 5 WT cases and 5 cases with dual TNFRSF14 aberrations. Error bars show standard deviation. There were no significant differences in the level of expression of CD58, MHC class I and II, CD80 or CD86 in WT FL B cells and FL B cells with dual TNFRSF14 aberrations either before or after in vitro activation (P > .05 in 2-tailed unpaired Student t test). MFI, mean fluorescence intensity; ns, not significant.