Complex sentence: Whereas Gc-MAF was originally touted as a 100% cure for some cancers, the research conducted by Nobuto Yamamoto and colleagues that prompted such claims has been called into question, and one of the original studies, published in 2007, was retracted in 2014.
Split into simpler sentences: Whereas Gc-MAF was originally touted as a 100% cure for some cancers, the integrity of the research conducted by Nobuto Yamamoto and colleagues that prompted such claims has been called into question. One of the original studies, published by Yamamoto's group in 2007, was retracted in 2014.