Human MLK3, also known as Mixed Lineage Kinase 3, Mitogen-activated protein kinase kinase kinase 11, MAP3K11, PTK1, SPRK, and MGC17114, GenBank Accession No. NM_002419, a.a. 1-488, with N-terminal GST-tag, MW = 83 kDa, expressed in Sf9 cells via a baculovirus expression system.