CRTAC1 Full-Length MS Protein Standard (NP_060528), 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 glycosylated extracellular matrix protein that is found in the interterritorial matrix of articular deep zone cartilage. This protein is used as a marker to distinguish chondrocytes from osteoblasts and mesenchymal stem cells in culture. The presence of FG-GAP motifs and an RGD integrin-binding motif suggests that this protein may be involved in cell-cell or cell-matrix interactions. Copy number alterations in this gene have been observed in neurofibromatosis type 1-associated glomus tumors. Alternative splicing results in multiple transcript variants.