In contrast, we found several clear correlations with other stimuli or infections, whereby PPD triggered an enhanced IFN-γ (estimated effect 1.09 (95% CI: 0.34 to 1.85); p-value = 0.0063) and IL-2 (estimated effect (1.15 (95% CI: 0.23 to 2.09); p-value = 0.0217) release in BAL IGRA-positive donors (Fig 4 and S3 Table). This evidence concerns the gene IFNG and infection.