The fact is:

Well, yes, most scientists  use gene synthesis for expression improvement of their genes of choice in heterologous systems. This can be achieved via codon usage adaptation using Eurofins’ gene adaption and optimisation software “GENEius”. But there are many more advantages for using gene synthesis. Imagine your NGS data reveal a very interesting DNA sequence that you now want to analyse further. With gene synthesis you can simply order your DNA or RNA sequence, you just need to know the in silico sequence. Another advantage of gene synthesis is fast and reliable access to cDNA sequences that a few years ago would have been done via labour-, time- and cost-intensive cDNA synthesis. No RNA extraction, no RT-PCR, and no RACE is needed for getting perfect full-length cDNA when using gene synthesis. Unwanted restriction sites can be avoided during adaption and subcloning into your own expression vector is also possible. Of course you can combine your gene sequence together with promoter and enhancer elements, polyadenylation signals, restriction sites, etc.