It seems billion dollar baby of Silcon Valley, Elizabeth Holmes, is facing yet another unicorn-slaying moment as the fairy-take ending for Stanford drop-out looks increasingly distant after WSJ reports regulators are seeking ban the so-called "billionaire" from the blood-tsting business for two years after U.S. health inspectors have found serious deficiencies at Theranos Inc.'s laboratory in Northern California.

In a letter dated March 18, the Centers for Medicare and Medicaid Services said it plans to revoke the California lab's federal license and prohibit its owners, including Ms. Holmes and Theranos's president, Sunny Balwani, from owning or running any other lab for at least two years. That would include the company's only other lab, located in Arizona.

The two labs generate most of Theranos's revenue and are at the core of its strategy to revolutionize the blood-testing industry with new technology, user-friendliness and quick results.

The letter hasn't been released to the public, but a copy was reviewed by The Wall Street Journal.