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

Sentence1: An intense bright light produces a glare. 
Sentence2: Nuclear reactions in stars cause stars to produce bright glares.
bright

Sentence1: When kidney function is normal, creatinine is removed from the body by the kidneys. 
Sentence2: Nephrons are necessary to remove creatinine from the body.

creatinine