In R (on the application of Quintavelle) v Human Fertilisation and Embryology Authority, the defendant argued that as Cell Nuclear Replacement (CNR) was not listed under the Human Fertilisation and Embryology Act 1990, it could not be used in the UK, only IVF. However, the courts disagreed and used the purposive approach to interpret the Act. They decided that the purpose of the Act was to cover all embryology rather than just available treatments at the time the Act was passed.