Metastasis is a significant cause of cancer fatality. Lymph nodes are the most common sites of early metastasis. T cells act as protectors against early cancer spreading.

Researchers found that two types of CD8+ T cells exist with a distinct genomic profile:

– Tumor-fighting T cells can freely travel from lymph nodes into the bloodstream and back to the lymph nodes.

– Lymph node resident memory T cells: Tumor-fighting T cells that do not circulate in blood or tissue but rather stay in lymph nodes where they provide protection against cancer, especially in the case of melanoma.

These newly discovered resident T cells are essential to counteracting the earliest stages of cancer metastasis in melanoma, for example.