How is genetic engineering being used to modify biologic agents?

Genetic engineering gives scientists incredible flexibility to induce gain or loss of function in cells or to shift normally plastic cellular phenotypes more permanently towards a desired state. Genome editing can induce paracrine activity in normally inert cells through gene overexpression, promote cell-cell interactions by introducing genes for specific receptors, and even promote tissue formation through the promotion of growth factor and hormone genes. 

Genetic manipulation is also commonly used to create the cellular factories that drive biologics production. Historically, the genes encoding the desired end product would be introduced to cells using plasmids or viral vectors, but transfection/transduction efficiency and transience presented issues for long-term production efficiency. New gene editing techniques such as CRISPR are helping to remove this obstacle.