Biotechnology uses cellular and biomolecular processes from living cells to develop products and processes. It includes the fields of genetics, molecular biology, biochemistry, and synthetic biology. Applications include medicine, agriculture, and biofuels. It has the promise to revolutionise human health, transport, and worldwide food supply. In 2016, biotech centres had a combined global revenue of 139.4bn USD. The USA leads the way in patents, followed by the EU and Japan. The largest biotech firms by market capitalisation in 2019 were Amgen (126.5bn USD), Novo Nordisk 103.6bn), CSL (80.3bn), Gilead Sciences (80bn), and Celgene (76bn). Biotechnology began with ancient cultures like the Ancient Egyptians who used yeast to make bread and beer. Modern biotechnology began with Gregor Mendel. Through experiments in plant hybridisation he developed the idea of genetic inheritance. In 1928, Alexander Fleming serendipitously discovered penicillin – a breakthrough in medical biotechnology and history. In 1957, James Watson and Francis Crick discovered the double helix structure of DNA and its importance to the functioning of DNA. This paved the way for genetic manipulation and genome sequencing in the 1970s and 1980s. The first splicing of DNA from one organism to another was done by Herbert Boyer and Stanley Cohen in 1973. This advance helped give birth to the modern biotech industry which was initially led by start-ups. In 1980, the US Supreme court ruled that isolated gene sequences could be patented but this was later overturned in 2013 partly with the hope that it would promote greater research. The first mammal, Dolly the sheep, was cloned from adult sheep cells in 1996 by Ian Wilmut. In 2013, Feng Zang was able to use a CRISPR to target and edit specific genes in mice and human cells. In terms of the business climate for biotech, the sensational IPOs of the late 20th century have given way to focused start-ups with the expectation of future acquisition by larger firms.