Joseph Schlessinger's former colleagues at the Weizmann Institute, in particular Michael Sela, claimed to have come up with this concept alongside Schlessinger when they worked together there years earlier, and Yeda challenged the Aventis patent in the United States. Schlessinger testified in court that the idea of combining the anti-EGFR antibody that his lab had developed with chemotherapy in cancer treatment was his own idea. However, the Weizmann Institute scientists provided extensive documentation that they had been developing this idea using an antibody against EGFR that Schlessinger's laboratory had developed and generated, and that he had given them for these studies. Schlessinger claims to have initiated the idea of this use in combination therapy, but had not documented his research and ideas as thoroughly, leaving him forced to rely on his recollections of the events that led to the patent filing some 17 years before Yeda mounted their challenge.