Linker of Activated T cells also known as LAT is a protein which is encoded by the LAT gene. Alternative splicing results in multiple transcript variants encoding different isoforms.

The protein encoded by this gene is phosphorylated by ZAP70/SYK protein tyrosine kinases following activation of the T-cell antigen receptor (TCR) signal transduction pathway. This transmembrane protein localizes to lipid rafts (also known as glycosphingolipid-enriched microdomains or GEMs) and acts as a docking site for SH2 domain-containing proteins. Upon phosphorylation, this protein recruits multiple adaptor proteins and downstream signaling molecules into multimolecular signaling complexes located near the site of TCR engagement.