Scientists are looking closely at a specific type of immune cell called CD38+ NK cells. These cells help the body fight infection and keep cancer in check. A recent narrative review examined how these cells change in people with rheumatoid arthritis and colorectal cancer. The findings are still very early, but they offer a new way to think about how the immune system fails in these diseases.
The review found that these immune cells appear more often in the blood and tissues of people with these conditions. In people with colorectal cancer, a protein called HSPA1B was lower on these cells. In people with rheumatoid arthritis, that same protein was higher. In mice without these specific cells, tumors grew slowly. This suggests the cells might be important for stopping cancer growth.
The evidence is preliminary, meaning it is not yet ready to change how doctors treat patients. However, this work provides a reference for understanding disrupted immune tolerance and surveillance. It helps explain why the body sometimes lets cancer grow or attacks healthy joints. More research is needed to see if targeting these cells could help patients in the future.