To test this, bulk T cell responses following primary SSTI or sublethal pneumonia in the draining lymph nodes (dLNs; pneumonia – mediastinal, SSTI – inguinal, hatched bars) on day 7 after infection were quantified by flow cytometry for the following CD4+ T cell subsets: Th17 (RORγt+), Th1 (T-bet+), regulatory T cells (Treg; FoxP3+), and follicular helper T cells (Tfh; CXCR5+)(model, Figure 3A, gating strategy Figure S2). This evidence concerns the gene CD4 and susceptibility to pneumonia measurement.