To determine whether IL-37 affects acquired immunity during BCG infection, we infected mice i.n. with BCG and quantified splenic T cells including Treg, Th1, Th17 cells by flow cytometry over 4 weeks p.i. We observed higher frequency of CD3+ T cells in IL-37-Tg mice at 2 weeks post infection with BCG, manifesting with increased frequency of CD4+ T cells but not that of CD8+ T cells among the CD3+ T cells (S2 Fig). This evidence concerns the gene IL37 and infection.