TLR4 signals have shown inconsistent effect (increased, decreased, and no effects) on T1D incidence (68–70), but one study has reported that agonistic TLR4/MD-2 Ab could substantially increase the number of Foxp3+Helios+Nrp-1+ Treg subset in pancreatic islet (67). Here, TLR4 is linked to type 1 diabetes mellitus.