While many bacteria may be targeted directly by the LRR domains of the proteins that were tested, obvious candidates for future investigation are Mycobacteria for Nod2, Legionella pneumophila for NAIP and Mycobacterium leprae for TLR2 due to the evidence associating these proteins with susceptibility to infection in cells, animal models and their genetic links with patient populations [13],[21]–[26]. This evidence concerns the gene NAIP and infection.