Currently, we are unable to synthesize genes that score as Impossible. There are several factors that cause our algorithm to score a gene Impossible and the specific parameters are unique to the gene sequence. Our algorithm is proprietary and was developed using machine learning. In addition to machine learning, our algorithm does take into consideration the following factors: %GC between 25-65% Max homopolymer length < 10 Low homology A unique combination of the above is a reflection of the specific gene sequence score of Impossible.