CD40LG and inflammatory bowel disease: We first measured SARS-CoV-2 spike-specific cTfh cells (OX40+CD40L+ of CXCR5+CD45RA−CD4+ T cells) and observed fewer spike-specific cTfh cells in patients with IBD on IFX monotherapy (P = 0.035, Figure 2c), IFX combination therapy (P = 0.053, Figure 2c), and VDZ (P = 0.013, Figure 2c) than NHDs.