Human CXCL11 (C-X-C motif chemokine ligand 11), also known as I-TAC (Interferon-inducible T-cell alpha chemoattractant), is a proinflammatory chemokine belonging to the CXC chemokine family, which also includes CXCL9 (MIG) and CXCL10 (IP-10) that regulate T-cell recruitment during antiviral and inflammatory immune responses. In humans (Homo sapiens), CXCL11 is produced by macrophages, dendritic cells, epithelial cells, endothelial cells, and fibroblasts in response to interferon-γ (IFN-γ), viral infection, or inflammatory cytokines. CXCL11 signals primarily through the chemokine receptor CXCR3, which is expressed on activated T lymphocytes, natural killer (NK) cells, and other immune cells, promoting chemotaxis and activation of these cells at sites of infection or inflammation. CXCL11 has a particularly high affinity for CXCR3 and plays a key role in Th1-type immune responses and antiviral immunity, especially in infections such as hepatitis viruses, influenza, and SARS-CoV-2. Dysregulated CXCL11 expression has also been associated with autoimmune diseases, chronic inflammatory disorders, and tumor-associated immune responses, where CXCR3-mediated T-cell trafficking influences immune cell infiltration into inflamed tissues or tumors. Because of its role in interferon-driven immune signaling and T-cell recruitment, human CXCL11 is widely studied in immunology, infectious disease research, cancer immunology, and development of therapies targeting inflammatory and immune-mediated diseases.