Give the function of histiocytes.

Explanation

### Step-by-Step Solution:

1. **Definition of Histiocytes**: Histiocytes are a type of white blood cell that plays a crucial role in the immune system.

2. **Formation**: Histiocytes are formed in the bone marrow, which is the spongy tissue inside bones where blood cells are produced.

3. **Main Function**: The primary function of histiocytes is to act as a defense mechanism for the body. They are part of the immune response.

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