PECAM1 and Oral ulcer: Lower TLR4 (p = 0.001) and TGF-β (p < 0.001) expression, alongside increased CD31 immunostaining (p < 0.001), were observed in GTA3 and GTA9, as well as reduced TLR2 expression (p = 0.001) in GTA9.<h4>Conclusion</h4>Alogliptin delays oral ulcer healing by sustaining inflammation, reducing TGF-β expression, and impairing collagen deposition, and may contribute via reduced TLR2/TLR4 expression, increased microbial burden, and decreased TGF-β.