Organ donation is the process when a person allows an organ of their own to be removed and transplanted to another person, legally, either by consent while the donor is alive or dead with the assent of the next of kin. Donation may be for research or, more commonly, healthy transplantable organs and tissues may be donated to be transplanted into another person. Common transplantations include kidneys, heart, liver, pancreas, intestines, lungs, bones, bone marrow, skin, and corneas. Some organs and tissues can be donated by living donors, such as a kidney or part of the liver, part of the pancreas, part of the lungs or part of the intestines, but most donations occur after the donor has died. In 2017 Spain had the highest donor rate in the world at 46.9 per million people, followed by Portugal (34.0 per million), Belgium (33.6 per million), Croatia (33.0 per million) and the US (32.0 per million). As of February 2, 2019, there were 120,000 people waiting for life-saving organ transplants in the US. Of these, 74,897 people were active candidates waiting for a donor. While views of organ donation are positive, there is a large gap between the numbers of registered donors compared to those awaiting organ donations on a global level. To increase the number of organ donors, especially among underrepresented populations, current approaches include the use of optimized social network interventions, exposing tailored educational content about organ donation to target social media users.