Make a Contribution Your gift to the Osteosarcoma Institute will impact our ability to transform lives and improve the life expectancy of relapsed and metastic patients. Two ways to contribute To make a tax deductible contribution, please mail checks made out to Osteosarcoma Institute to: 100 Crescent Court Suite 700 Dallas, Texas 75201 To make a tax deductible contribute via Paypal, please click the button below. Donate now The Osteosarcoma Institute (OSI) is a 501(c)(3) public, non-operating foundation, IRS identification 82-2921815. Click here to download a copy of our exemption letter. The OSI is committed to transparency in its investment processes, and to rapid reporting of results.