The leukemia charity, Anthony Nolan Trust, is to encourage people to spit so as to use saliva for matching bone marrows.

"Ultimately, this is about saving more lives. Anthony Nolan provides two potentially lifesaving transplants every day, but there is an equal number that we can't currently help,” said Henny Braund, chief executive of Anthony Nolan. "We urgently need to increase the number of people on our register, and saliva testing will help us do that much more quickly and effectively."
The charity’s research team has found that saliva tests are just as effective as blood typing. The charity has already run a pilot program that has seen 5,000 people join its register.
Source-Medindia