Myeloid differentiation primary response protein 88 (MyD88) is a critical adaptor protein involved in Toll-like receptor (TLR) and interleukin-1 (IL-1) receptor family signaling controlling innate immune responses and inflammation. MyD88 links IL-1 receptor (IL-1R) or TLR family members to IL-1R-associated kinase (IRAK) family kinases via homotypic protein-protein interaction. Activation of IRAK family kinases leads to a variety of functional outputs, including the activation of nuclear factor-kappa B (NFκB), mitogen-activated protein kinases, and activator protein 1, making MyD88 a central node of inflammatory pathways. Genetic deletion of MyD88 function results in profound suppression of inflammation and reduced resistance of the host to pathogens indicating non-redundant roles of MyD88. Detection of MyD88 expression was to predict the prognosis of various human cancers, e.g., lymphoid, liver, and colorectal cancers.