CT-133 is a selective and potent CRTH2 Receptor antagonist, with a Ki value of 2.2 nM. The Ki value for the DP1 receptor is greater than 3800 nM. CT-133 inhibits neutrophil migration induced by PGD2 (HY-101988). CT-133 significantly alleviates lung inflammation and improves lung function impairment in a mouse model of acute lung injury (ALI) induced by cigarette smoke. CT-133 effectively inhibits the excessive expression of pro-inflammatory cytokines (TNF-alpha, IL-1beta, and IL-6) and chemokines (KC), and reverses the inhibition of the anti-inflammatory factor IL-10. CT-133 can be used for the study of ALI[1].