The investment seeks to track the investment results, before fees and expenses, of the TIAA ESG USA Mid-Cap Growth Index (the index). Under normal market conditions, the fund invests at least 80% of the sum of its net assets and the amount of any borrowings for investment purposes in component securities of the index. The index is comprised of equity securities with growth characteristics issued by mid-capitalization companies listed on U.S. exchanges that meet certain environmental, social, and governance (ESG) criteria.