As discussed, new uses may be denied product patent protection to the extent that the (known) product in question fails the novelty test, either on the basis of a specific regulation governing novelty in such cases, or on the basis of case-by-case examination. In addition, process patent protection may be denied where domestic laws implement a broad exemption from patentability for methods of medical treatment, in accordance with Article 27.3 (a) of the TRIPS Agreement. Variations in the DNA sequences of humans can affect how humans develop diseases, respond to pathogens, chemicals, drugs, etc.