Elevated MMP-9 levels were also demonstrated by Devillers et al. (2007) [83] and Wang et al. (2024), who further identified the TLR2/TLR1 signaling pathway as the main mechanism by which MMP-9 contributes to inflammation and pruritus in allergic contact dermatitis [84]. The gene discussed is MMP9; the disease is allergic contact dermatitis.