Answer:
No, they don't.
Explanation:
Trees need leaves for photosynthesis because leaves contain chlorophyll. As the article states, the food-making process stops after these trees lose their leaves. Some trees keep their leaves all year long.
In rheumatoid Arthritis patients, NK cell levels were abnormally elevated, possibly due to high serum levels of IL-2.
Rheumatoid arthritis (RA), is an autoimmune disease that means our own immune system attacks self healthy cells in the body by mistake, causing inflammation (painful swelling),mainly attacks the joints.
The given study is to investigate the relationship between serum interleukin-2 (IL-2) levels and disease activity.
This study also showed the relationship between absolute numbers of peripheral lymphocyte subsets, autoantibodies, and associated cytokines in patients with rheumatoid arthritis (RA).
The results showed that the number and percentage of NK cells were positively correlated with serum IL-2 levels so, IL-2 can be a reason for elevated level of NK cells
Learn more about Rheumatoid arthritis on
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The skeletal system<span> performs vital </span>functions<span>— support, movement, protection, blood cell production, calcium storage and endocrine regulation — that enable us to survive.</span>
