Our efforts focused on a single gene, KRas4B, as a case study because the native CDS contains a significant number of rare codons (median codon frequency = 0.34), it is a therapeutically important target implicated in a wide variety of cancers [48], codon usage has been tied to expression levels in bacteria and mammalian cells [44, 49, 50], and there are several reports publishing their CDS with purified yield (enabling correlation of CDS with recombinant product). Here, KRAS is linked to cancer.