BLEAT provides a rank order for candidate stem cell sources (“donors”) to optimize therapy selection and patient outcomes. The BLEAT user interface (left) has an infographic (right) that is toggled via the Help button (A). On the interface, users enter HLA-B typing information for each subject. (A) The patient’s leader genotype (MM, MT, or TT) is automatically classified upon entering the patient’s HLA-B typing. Ambiguous alleles can sometimes contain rare leader variants; the tool highlights this possibility in red. (B) HLA-B allele typing for donors can be manually entered or automatically imported. Before or during sorting, (C) the leader match status for each donor (matched with the patient) is calculated. Once calculated, a donor selection guide (D) highlights each selected donor’s relative level of risk for acute GVHD based on the patient’s leader genotype and published outcomes.¹³  The match status for each donor (E) is displayed through HapLogic match grades (A, allele match; P, potential match; L, allele mismatch; M, antigen mismatch)³⁷  and leader match status (eg, MTT, a 3-letter nomenclature used to designate the leader of the patient’s mismatched HLA-B [first letter], the leader of the donor’s mismatched HLA-B [second letter], and the leader of the shared/matched HLA-B [third letter]).¹³