The fund invests primarily in common stocks of companies engaged in the research, development, production, or distribution of products or services related to health care, medicine, or the life sciences. It will invest at least 80% of its net assets, under normal circumstances, in equity securities of health science companies. The fund invests primarily in common stocks of U.S. companies, but may, to a lesser extent, invest in equity REITs, common stocks of foreign companies and American Depositary Receipts ("ADRs") that meet the investment criteria of the fund.