Within the lung tissue of Clarithromycin-treated mice, we found diminished frequencies and numbers of CD4+ IL-17A+ T cells (Fig. 1a, b) when compared with mock treatment, while the frequency and numbers of CD4+ IFN-gamma+ T cells (Fig. 1c, S1a) were unimpaired 7 days post-infection (p.i.). Here, IFNG is linked to infection.