US STOCKS-Wall St slips to snap six-day rally; biotechs weak By: Reuters: Company News April 23, 2014 at 16:38 PM EDT * Dow off 0.08 pct; S&P 500 down 0.22 pct; Nasdaq off 0.83 pct (Updates to close, adds Facebook earnings) Read More >> Related Stocks: AT&T Inc Amgen Biogen Idec Boeing Co D.R.Horton Facebook Gilead Sciences Illumina Inc Verizon Communications