Disease resistance protein. Resistance proteins guard the plant against pathogens that contain an appropriate avirulence protein via a direct or indirect interaction with this avirulence protein. That triggers a defense system including the hypersensitive response, which restricts the pathogen growth (By similarity). Interacts with MED37E. Mostly present in shoots. In some plant proteins and in human SARM1, the TIR domain has NAD(+) hydrolase (NADase) activity (By similarity). However, despite the presence of the catalytic Asp residue, the isolated TIR domain of human TLR4 lacks NADase activity (By similarity). Based on this, it is unlikely that Toll-like receptors have NADase activity.