Fig 2: Box plots indicating the differences in peptide levels in (A) serum and (B) BALF among the different groups. A total of 8 peptides were identified to be differentially expressed in serum, including those with an m/z of 1,180.93 (myeloid-associated differentiation marker), 6,844.58 (undefined peptide), 2,660.56 (fibrinogen a-chain), 1,532.24 (clusterin), 4,300.83 (keratin, type I cytoskeletal 18), 4,419.72 (APOAI), 4,185.05 (AGT) and 6,816.51 (undefined peptide). Furthermore, 9 peptides were identified to be differentially expressed in BALF, including those with an m/z of 4,169.49 (APOAI), 7,929.01 (undefined peptide), 4,200.65 (argininosuccinatelyase), 4,186.06 (AGT), 4,533.75 (APOAI), 5,278.1 (undefined peptide), 5,763.15 (undefined peptide), 6,701.81 (undefined peptide), 6,029.68 (undefined peptide). Relative levels (fold change) of the proteins were presented in the box plots. Groups: 1 (red), tuberculosis; 2 (green), tracheal intubation and tracheotomy; and 3(blue), early-stage lung cancer. BALF, bronchial alveolar lavage fluid; m/z, mass-to-charge ratio; APOAI, apolipoprotein A-I; ATG, angiotensinogen.