A Practice Note addressing US Patent and Trademark Office (USPTO) subject matter eligibility rejections under 35 U.S.C. § 101 of claimed inventions covering biopharma and other life sciences-related inventions, including nature-based products and compositions, medical treatment methods, and diagnostic tests. This Note discusses US Supreme Court and US Court of Appeals for the Federal Circuit patent eligibility decisions and the USPTO's subject matter eligibility examination guidance. It includes suggestions for responding to rejections based on the natural phenomenon, natural law, and abstract idea judicial exceptions to patent subject matter eligibility.