The U.S. Supreme Court has decided not to review a lower court’s decision to invalidate one of Sequenom’s patents.

Sequenom Inc., a diagnostic company in San Diego, has been involved in a series of lawsuits that began in 2011 concerning Sequenom, Ariosa Diagnostics, and Natera Inc.

The patent in question, U.S. Patent No. 6,258,540, covered the detection of cell-free DNA in the bloodstream of pregnant women. The patent was invalidated in 2013 because it covers a phenomenon of nature, which is unpatentable, according to the court. That decision was upheld at an appeals court earlier this year.

In a statement, Sequenom said the Supreme Court was "uniquely suited to reconcile" patent ineligibility criteria established in the Mayo Collaborative Services v. Prometheus Laboratories decision, which the federal district courts cited in deeming Sequenom's patent invalid.

“We are disappointed that the Supreme Court denied our petition and will not review the patent eligibility of the groundbreaking techniques embodied in the '540 Patent'," said Dirk van den Boom, president and CEO of Sequenom, in a statement. "We believe that the Supreme Court missed an ideal opportunity to clarify patent eligibility criteria not only to protect the significant investments made by Sequenom but also by other innovative organizations to advance the standard of patient care and treatment. We fear this decision will discourage such investments in the future."

Sequenom stated that the ruling has little business impact as it has already been operating under the District Court's invalidity ruling since 2013 and due to the intellectual property pooling arrangement the company entered into with Illumina Inc. in 2014.