TLR4 and periodontal disorder: On the other hand, it has been observed that the expression of TLR2 and TLR4 in gingival epithelial cells is higher in individuals with diabetes and is positively regulated according to the severity of periodontal disease [73], and that TLR2 and TLR4 would have a role in the control of infection by A. actinomycetemcomitans [74,75].