MYD88 and mucopolysaccharidosis: It is well known that stimulation of TLR4 induces signaling cascades through MyD88 (myeloid differentiation factor 88) dependent and/or MyD88 independent (TRIF-dependent) pathways, leading eventually to the activation of NF-kB, AP-1, and IRF-3 transcription factors, but which one of the three may play a more important role in inducing the up-regulation of CD274 expression in MPS is still unknown.