Generate an overlapping word between the given two sentences. When you find the overlapping words, they don't have to match exactly, e.g., "survival" and "survive" are valid overlapping words. Little words like "the" or "of" don't count! You must generate significant words which are not the stop words.

Sentence1: For example, insulin is a protein hormone. 
Sentence2: Insulin is produced in a part of the cell called the ribosome.
insulin

Sentence1: wind is used for producing electricity. 
Sentence2: Winds are caused by pressure differences.
wind

Sentence1: Fractures heal when osteoclasts form new bone. 
Sentence2: Bones and teeth are made of calcium.

bone