Detailed Instructions: From the given sentence, extract the phrase (often noun or verb) that carries the given relationship. The generated phrase should be present in the sentence.
Problem:Given Relationship: 'be lead by', Sentence: 'The genetically engineered protein vaccine , called RiVax , was developed as an outgrowth of cancer therapy work on the part of a UT team led by Dr. Ellen Vitetta , director of the UT Southwestern Cancer Immunobiology Center .'
Solution:
led