MEF2B Full-Length MS Protein Standard (NP_001139257), 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. The product of this gene is a member of the MADS/MEF2 family of DNA binding proteins. The protein is thought to regulate gene expression, including expression of the smooth muscle myosin heavy chain gene. This region undergoes considerable alternative splicing, with transcripts supporting two non-overlapping loci (GeneID 729991 and 100271849) as well as numerous read-through transcripts that span both loci (annotated as GeneID 4207). Several isoforms of this protein are expressed from either this locus or from some of the read-through transcripts annotated on GeneID 4207.