TLR4 and arthritic joint disease: In the same way, the increased sensitivity of C3H/HeJ mice to severe arthritis caused by live M. arthritidis is associated with type 1 cytokine profile, whereas, BALB/c mice (TLR4+) display a type 2 cytokine profile in response to MAM and develop a mild arthritis caused by M. arthritidis [289,296], indicating that MAM differentially regulates the cytokine response by unique interaction with TLRs, and this interaction may be associated with the severity of disease induced by M. arthritidis.