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.
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Question: Sentence1: Lymphocytes are the key cells involved in the immune response. 
Sentence2: The key cells involved in the immune response produce antibodies.

Answer: cells


Question: Sentence1: folding an object causes that object to change shape. 
Sentence2: Folding an object causes that object to transform.

Answer: causes


Question: Sentence1: plasma is formed by electrons separating from atoms in stars. 
Sentence2: Plasma Is the liquid portion of the blood.

Answer:
plasma