PTGDR2 and asthma: In our study, we found that CRTH2 antagonists, compared to placebo, significantly improved pre-bronchodilator FEV1 (L) and AQLQ scores, reduced ACQ scores and SABA use in adults with asthma, which was also true in the treatment of CRTH2 antagonists monotherapy except for no effect on ACQ scores but improved pre-bronchodilator FEV1% predicted and reduced asthma exacerbations.