The number of DP2+ epithelial cells was significantly reduced in biopsy specimens from patients with moderate and severe asthma compared with those from healthy control subjects (Fig 1, G; mean [SEM]: 30 [5] vs 72 [11]/10 mm2 epithelium, P = .036; 21 [3] vs 72 [11]/10 mm2 epithelium, P = .001) and in biopsy specimens from patients with severe asthma compared with those from patients with mild asthma (mean [SEM]: 21 [3] vs 54 [8]/10 mm2 epithelium, P = .027). Here, PTGDR2 is linked to asthma.