Human CSK also known as C-Terminal Src Kinase, Protein-Tyrosine Kinase CYL, C-Src Kinase and C-Src Tyrosine Kinase, GenBank Accession No. NM_004383, a.a. 1-450(full length) with N-terminal GST-His-Th-tag, expressed in Sf9 cells via a baculovirus expression system. MW = 80 kDa.