BPIFB1 and chronic rhinosinusitis with nasal polyps: Real-time PCR analysis demonstrated that glucocorticoid treatment for 2 weeks significantly increased the expression of BPIFA1 (P < 0.001), BPIFB1 (P < 0.05), BPIFB2 (P < 0.05), LTF (P < 0.01), SLPI (P < 0.001), and CLU (P < 0.001), but not LYZ, in nasal tissue of patients with CRSwNP (Figure 4).