Agrin is a large proteoglycan whose best-characterised role is in the development of the neuromuscular junction during embryogenesis. Agrin is named based on its involvement in the aggregation of acetylcholine receptors during synaptogenesis.

1. He stood there, agrin, waiting for the good news.
   他微笑著站在那里，等待好消息。
2. The children played happily in the park, their faces agrin with joy.
   孩子們在公園里快樂地玩耍，臉上洋溢著歡快的笑容。