TLR2 and parasitic infectious disease: Previous studies found that TLR2 was upregulated when exposed to extracellular vesicles, soluble antigens, and glycosylphosphatidylinositols (GPIs) from N. caninum or parasite infection and regulated the secretion of a variety of cytokines (Mineo et al., 2010; Li et al., 2018; Debare et al., 2019).