Themis is a 641 amino acid nuclear and cytoplasmic protein that exists as three alternatively spliced isoforms. Themis belongs to the themis family and interacts with PLC γ1, Emt and GRB2. Acting through T-cell antigen receptor (TCR) signaling and through the regulation of calcium influx and phosphorylation of ERK 1, Themis plays a central role in late thymocyte development by controlling both positive and negative T-cell selection. Themis is phosphorylated on Tyr residues quickly after