Individual states have passed differing laws regarding human biotechnologies, creating an often inconsistent policy patchwork across the country. This is particularly the case with regard to human reproductive cloning, embryo cloning for stem cell research, and surrogacy. While more than a dozen states prohibit human reproductive cloning, the rest have not addressed it in law. Several states prohibit the creation of cloned human embryos for stem cell research, while others – notably California, which prohibits reproductive cloning – have invested billions of dollars in stem cell research programs that fund it. Laws and regulations pertaining to assisted reproduction, especially surrogacy, also vary significantly from state to state.