Mention one function of the protein hirudin.

Explanation

**Step-by-Step Solution:**

1. **Understanding Hirudin**: Hirudin is a protein that is produced by the leech species Hirudo medicinalis, which is a blood-sucking leech. It is a recombinant protein that can be produced using biotechnology.

2. **Function of Hirudin**: The primary function of hirudin is to act as an anticoagulant. This means it prevents blood from clotting.

3. **Mechanism of Action**: When a leech attaches to its host to feed, it secretes hirudin into the host's bloodstream. This prevents the blood from clotting, allowing the leech to feed more effectively.

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