KIR Genotyping Data of More Than 3 Million Individuals Are Available for Global Unrelated Stem Cell Donor Searches (Comment to: Weisdorf D, Cooley S, Wang T, et al. KIR donor selection: feasibility in identifying better donors. Biol Blood Marrow Transplant. 2018; doi: 10.1016/j.bbmt.2018.08.022.)