Developing countries, by taking foreign expertise into account, may considerably elevate the level of ordinary skill in the relevant prior art, thereby increasing the likelihood of a negative finding on the inventive step/non-obviousness requirement. Members are free to set up certain criteria for determining cases of (non-)obviousness in specific product areas. In the pharmaceutical context, for example, it is often assessed in terms of the predictability of the claimed invention, based on prior art teachings. Moreover, under United States Federal Circuit case law, structural similarities between a prior art chemical compound and a claimed substance may under certain circumstances establish a prima facie case of obviousness of the claimed invention.189 Also, the presence of a reasonable expectation of success to come up with the new product may be considered an indication of obviousness, especially when multiple prior art references must be combined.