ER stress in asthmatic patients and a graphical abstract of Lyn-regulated ER stress and mucus secretion in asthma. Biopsy specimens were collected from the right middle lobar bronchi. Ages of asthmatic patients (years, mean ± s.d), 44.35 ± 7.21; control subjects, 39.47 ± 6.19. Forced expiratory volume in one second (FEV1%) in patients, 75.13 ± 6.28; Control subjects, 92 ± 4.26.(a)Representative H&E–stained sections of biopsy specimens (original magnification, × 100). (b–d) Confocal laser immunofluorescence photomicrographs of BIP, CHOP and IL-13 in asthmatic patients (original magnification, × 200). Four patients (males) with asthma and four control subjects (males). (e–g) The fluorescence intensity of BIP, CHOP and IL-13 were quantified in epithelial cells. Bars represent the mean ± s.d (n = 4 each group, Mann-Whitney U test was used for Statistical analysis). (h) Graphical abstract of Lyn-regulated ER stress and mucus secretion in asthma.