This group synthesized proteins in a cell-free system using components purified from E. coli (PUREexpress protein synthesis kit, New England Biolabs) with dyhydrofolate reductase (DHFR) and DNA from postmortem brain tissues of three human patients (control, Alzheimer’s disease and ALS) as templates. The gene discussed is DHFR; the disease is amyotrophic lateral sclerosis.