The potential for compensation between innate immune signaling pathways provided a rationale for testing the effect of the dual loss of TLR2 and TLR9, with the expectation that Tlr2/9−/− mice would have reduced bone loss, reduced osteoclast surface, and less dysregulation of bone homeostasis during osteomyelitis. The gene discussed is TLR9; the disease is osteomyelitis.