By Colin Kellaher 



  Healthcare company Grail Inc. on Wednesday filed with the U.S. Securities and Exchange Commission for a proposed initial public offering. 


  Grail's filing indicates it plans to raise $100 million, although that figure is often used as a placeholder to calculate filing fees. 


  The Menlo Park, Calif., company, which focuses on the early detection of cancer, said it has applied to list its shares on the Nasdaq Global Select Market under the symbol GRAL. 


  Grail's backers include Illumina Inc., which currently holds a 14.6% stake, and Johnson & Johnson, which owns a 7.6% interest. 


  Illumina launched Grail in 2016 with a group of other investors aiming to develop and market a test to detect genetic evidence of cancer in the blood. 


  Grail in May said it had raised $390 million in a Series D funding round. 


  Write to Colin Kellaher at colin.kellaher@wsj.com