MAP4K4 and medulloblastoma: Latter is of particular relevance in the context of the association of high MAP4K4 expression with the invasive behavior of tumors spreading in the central nervous system (CNS) - such as the most common malignant pediatric brain tumor medulloblastoma (6), or glioblastoma (7) - where MAP4K4 expression is high in certain cellular compartments also under physiological conditions.