eEF1A1 is an isoform of the alpha subunit of the elongation factor 1 complex, which is responsible for the enzymatic delivery of aminoacyl tRNAs to the ribosome. It promotes the GTP dependent binding of aminoacyl tRNA to the A site of ribosomes during protein biosynthesis. This isoform (alpha 1) is expressed in brain, placenta, lung, liver, kidney, and pancreas, and the other isoform (alpha 2) is expressed in brain, heart and skeletal muscle. This isoform is identified as an autoantigen in 66% of patients with Felty syndrome (referenced from entrez gene and swissprot).