Definition: 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: Hormone therapy Hormones are substances that occur naturally in the body. 
Sentence2: Substances in the pituitary control the endocrine glands.

substances