CCL19, a member of the chemokine CC family, is highly expressed in tumours and is able to recruit CD8+ T cells and mature dendritic cells (DCs) to infiltrate the tumour core, forming an “immunothermal microenvironment” and promoting the formation of tertiary lymphoid structures (TLS) to enhance the local anti-tumour immune response (Iida and Harada, 2024). The gene discussed is CCL19; the disease is neoplasm.