Similarly, stimulation with SEB, a superantigen also utilized as a positive control, resulted in significantly higher IFN-γ concentrations in the healthy controls relative to the group of proven PJP cases (p = 0.0078, Table 4, Figure 1b) as well as compared to the immunocompromised control group (p = 0.0002, Table 4, Figure 1b). Here, IFNG is linked to pneumocystosis.