Cells that produce paracrine factors secrete them into the immediate extracellular environment.

Now, researchers have avoided this problem by getting small populations of bacteria to produce soluble factors that act as circuit wires.

Many microbes, especially bacteria, produce numerous factors that are released into the environment beyond the cell membrane.

Macrophages are stimulated by the low oxygen content of their surroundings to produce factors that induce and speed angiogenesis.

When macrophages and other growth factor-producing cells are no longer in a hypoxic, lactic acid-filled environment, they stop producing angiogenic factors.

Tumors can produce several other factors that also promote blood vessel formation, however, so blocking the growth factor alone might not be sufficient, scientists said.

With colleagues, he discovered that BCC produce soluble factors increasing osteoclast activity, notably interleukin-11, the production of which is reduced by the cyclooxygenase inhibitor aspirin.

A hemophiliac, for instance lacks the ability to produce factors that cause the blood to clot.

From an anti-inflammatory standpoint, fat tissue produces various anti-inflammatory factors with the most commonly described being adiponectin.

This is despite of their capacity to produce 'good' economic factors or employment opportunities.