Ests that opioids, such as morphine, can interact with MD2, causing a similar activation of a functional TLR4 signaling unit. Ensuing intracellular signaling occurs through toll-interleukin 1 receptor domain containing adaptor protein (TIRAP) to at least three parallel pathways: cell motility and cell survival/apoptosis occur through the phosphatidylinositol 3-kinase (PI3K)/Akt pathway, and proinf