TPBG Full-Length MS Protein Standard (NP_006661), Labeled with [U- 13C6, 15N4]-L-Arginine and [U- 13C6, 15N2]-L-Lysine, was produced in human 293 cells (HEK293) with fully chemically defined cell culture medium to obtain incorporation efficiency at Creative-Proteomics. This gene encodes a leucine-rich transmembrane glycoprotein that may be involved in cell adhesion. The encoded protein is an oncofetal antigen that is specific to trophoblast cells. In adults this protein is highly expressed in many tumor cells and is associated with poor clinical outcome in numerous cancers. Alternate splicing in the 5 UTR results in multiple transcript variants that encode the same protein.