The present invention provides antibodies that bind to the T cell co-inhibitor lymphocyte activation gene 3 (LAG3) protein, and methods of use. In various embodiments of the invention, the antibodies are fully human antibodies that specifically bind to LAG3. In some embodiments, the antibodies of the invention are useful for inhibiting or neutralizing LAG3 activity, thus providing a means of treating a disease or disorder such as cancer or viral infection.本發明提供結合至T細胞共抑制分子淋巴球活化基因3(LAG3)蛋白的抗體及使用方法。在本發明的各種具體例中,該等抗體為特異地結合至LAG3的完全人類抗體。在一些具體例中,本發明抗體可用於抑制或中和LAG3活性,因而提供一種治療諸如癌症或病毒感染之疾病或病症的方法。