The omentum — an elastic apron of fat that stretches over our intestines, liver and stomach — may hold the key to battling obesity and cancer cell growth while simultaneously serving as the body's first line of defense against deadly toxins and infection, researchers are discovering.

Key functions:

• The omentum secretes hormones related to obesity and collects information about the health of the abdomen. However, scientists are still struggling to understand how this apron of fat is related to obesity as it serves in its protector role.
• It also appears to serve as the first stop inside our body for cells, antigens and bacteria before our immune system jumps into action by, for instance, releasing inflammatory molecules.

How it works: The telltale sign that the omentum is about to trigger the body's immune system response is the formation of small, white filters among the fat cells (called "milky spots"). We actually develop such "milky spots" on our omentum even before infectious bacteria shows up — a clear indication that this strange organ is central to our body's immune response.

What it gets wrong: Unfortunately, the omentum makes exactly the wrong decision with cancer cells, researchers said in the study. The omentum tolerates the cancer cells, rather than starting an immune response against them. What's worse, they actually trap some types of cancer cells and allow them to metastasize and grow more aggressively.