Of the 121,000 people on donor lists in the U.S., over 100,000 need kidney transplants and thousands die each year while waiting. Bioprinting aspires to build healthy kidney tissue from a patient's own cells and transplant this to boost failing kidneys without fear of rejection…As the 21st century dawned, a handful of inspired scientists tried to use 3D printing to create living human tissue. Their vision was to restore the health of people with intractable injuries, such as worn out cartilage, severed nerves, ailing kidneys, failing hearts?the gamut of human frailties.Their modest success energized others to join the quest. Now, after two decades of ingenious effort and hard work, they have carved out a vibrant new discipline: bioprinting.