The burgeoning field of protein science, and the resultant biological products, places ever growing demands on protein expression. Increasingly, researchers need to produce quality protein faster and in larger quantities to meet industry’s rising demands. Protein scientists must delve into genomic structure and function in order to understand and engineer expression systems, elucidate protein function and behavior, and overcome protein’s intrinsic challenges, such as aggregation and misfolding. Membrane proteins and other especially troublesome molecules pose even greater difficulties, yet hold considerable promise and rewards. The week-long Expression Stream focuses on productivity, from genes and clones, through production systems, and includes an examination of Difficult-to-Express Proteins along with breakthrough strategies and technologies in the pursuit of viable proteins.