TLR2 and infection: Although there is little published work on TLR2-dependent/MyD88-independent pathway(s), previous research involving in vitro infections of murine peritoneal macrophages with heat-killed M. tuberculosis was shown to result in the expression of the secretory leukocyte peptidase inhibitor gene (SLPI) via a TLR2-dependent/MyD88-independent pathway [56].