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.

[EX Q]: Sentence1: Protein Protein is needed for tissue maintenance and repair. 
Sentence2: protein repairs cells.
[EX A]: Protein

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

[EX Q]: Sentence1: When larvae are swallowed by the cat, hookworm infection is established. 
Sentence2: hookworm infection is established when hookworm enter through the skin.
[EX A]:
established