NEW YORK ( TheStreet) -- CHANGE IN RATINGSADC Telecom ( ADCT) downgraded at Jefferies from Buy to Hold. See limited upside to the $12.75 takeover bid from TEL. Amerigroup ( AGP) initiated at Citi with a Buy rating and $45 price target. Favorable overall view of Medicaid, and Amerigroup is our favorite name. AK Steel ( AKS) upgraded at Goldman from Neutral to Buy. $17 price target. Company should benefit from falling iron ore prices. Allstate ( ALL) rated new Perform at Oppenheimer. Agency network is the company's most valuable asset. Codexis ( CDXS) initiated at Credit Suisse with an Outperform rating and $17 price target. The company's gene shuffling platform technology and blue chip customers create long-term value. Centene ( CNC) initiated at Citi with a Buy rating and $27 price target. A significant portion of Centene's revenue was up for bid in first half of 2010, but the next six months look better. Salesforce.com ( CRM) upgraded at UBS. CRM was upgraded from Neutral to Buy. $111 price target. Estimates also boosted, given the opportunity for the Chatter product. eHealth ( EHTH) initiated at Citi with a Sell rating and $10 price target. Health care reform could decimate eHealth's business model. Energizer ( ENR) upgraded at UBS from Neutral to Buy. $63 price target. Stock is already pricing in lower earnings, and the company has room to cut costs. Illumina ( ILMN) rated new Perform at Oppenheimer. Stock is largely pricing in the company's growth potential. Keycorp ( KEY) rated new Negative at Susquehanna. $6 price target. Company needs to raise significant capital, which will dilute current investors. Lincoln National ( LNC) downgraded at Credit Suisse to Neutral from Outperform. We see heightened risk of LNC realizing impairments on either goodwill assets, DAC assets, or statutory reserves. Price target cut to $30. Lexmark ( LXK) downgraded at Morgan Stanley from Equal-weight to Underweight. Competition is heating up, and the company faces currency risks. MDC Holdings ( MDC) downgraded at Goldman to Neutral. Company was also removed from the Conviction Buy list, as the large land purchase will require higher operating costs.