The protein levels of KCNJ2 in BAL fluids, measured by ELISA, were significantly higher in IPF patients (6.587 [1.441–26.01] ng/mL) than those in NCs (0.084 [0.000–0.260] ng/mL; p < 0.001), NSIP patients (0.301 [0.070–5.059] ng/mL; p=0.006), HP patients (0.365 [0.000–3.407] ng/mL; p=0.02), and sarcoidosis patients (0.170 [0.057–1.179] ng/mL; p < 0.001) (Figure 2(a)). This evidence concerns the gene KCNJ2 and idiopathic pulmonary fibrosis.