Roche Holding AG began its 5.7 billion dollar hostile takeover offer for Illumina. This as investors signaled they expect the Swiss drugmaker to raise its bid for the gene-mapping company. Shareholders of Illumina have until midnight on February 24 to tender their shares at 44 dollars and 50 cents each, Roche said today in a statement. But the offer can be extended. Roche also wants to nominate six members of the Illumina board at the U.S. company’s annual meeting. Illumina’s stock has traded above the offer price since the announcement amid speculation of a higher bid. Roche Holding (NASDAQ:RHHBY) has potential upside of 25.4% based on a current price of $43.03 and an average consensus analyst price target of $53.95.