Given the task definition and input, reply with output. In this task, you are given a sentence. You are expected to recognize the name of gene or protein. Although there might be several correct answers, you need to write one of them.

 These findings present major differences in the early cell activation process between LPS and muramyl peptides , and strongly argue for the implication of co - receptors other than TLR2 and TLR4 in mediating the signaling events induced by defined subunits of bacterial peptidoglycans .

co - receptors