HEK 293 cells HEK 293 cells Human embryonic kidney 293 cells, also often referred to as HEK 293, HEK-293, 293 cells, or less precisely as HEK cells, are a specific cell line originally derived from human embryonic kidney cells grown in tissue culture. HEK 293 cells have been widely used in cell biology research for many years, because of their reliable growth and propensity for transfection. They are also used by the biotechnology industry to produce therapeutic proteins and viruses for gene therapy. HEK 293 cells were generated in 1973 by transfection of cultures of normal human embryonic kidney cells with sheared adenovirus
Climate change adaptation people who bear emission reduction costs or benefits are often different from those who pay or benefit from adaptation measures. Economists, using cost-benefit analysis, have attempted to calculate an "optimal" balance of the costs and benefits between climate change impacts, adaptation, and mitigation. There are difficulties in doing this calculation, for example, future climate change damages are uncertain, as are the future costs of adaptation. Also, deciding what "optimal" is depends on value judgements made by the economist doing the study (Azar, 1998). For example, how to value impacts occurring in different regions and different times, and "non-market" impacts, e.g.,