Following the revision of the European Patent Convention (EPC) in 2000, sections 1-5 of the Patents Act, 2004 will be brought into force on 13 December 2007, the same day that the revised EPC enters into force. The changes are concerned primarily with: patentability of substances for the use in methods of treatment or diagnosis; amendment of patents after grant and the automatic designation of states on filing of an EP application; and the prior art effect of EP applications in the UK.