Instructions: 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.
Input: Sentence1: Thyroid hormones increase the rate of metabolism in cells throughout the body. 
Sentence2: TSH, which is secreted by the pituitary gland, stimulates the thyroid gland to produce hormones.
Output:
Thyroid