PRF1 and tuberculosis: Total perforin levels were also significantly increased in PBMCs of ATB patients (3.50 ± 1.24 ng/mL) and LTBI patients (4.18 ± 1.07 ng/mL) in response to CFP10 stimulation as compared to healthy control subjects (1.64 ± 0.82 ng/mL) and non‐TB patients (1.87 ± 0.99 ng/mL), and ATB patients still had no statistical difference as compared with LTBI individuals (P = .057), (Figure 1C).