Fig. 1. MHC-I alleles with predicted binding to CALR^MUT-derived peptides are less frequent in CALR^MUT MPNs.

(A) Principal components analysis of MHC-I allele frequencies from patients with CALR^MUT MPN, patients with JAK2^V617F MPN, and U.S. Caucasian population. (B) Comparison of MHC-I allele frequencies from patients with CALR^MUT MPN, patients with JAK2^V617F MPN, and U.S. Caucasian population compared to each other in the NEUS cohort and (C) the Danish cohort. Frequencies are expressed as percentages. MHC-I alleles that are overrepresented in patients with CALR^MUT are in blue (NEUS cohort) and green (Danish cohort), whereas MHC-I alleles that are underrepresented in patients with CALR^MUT are in red (NEUS cohort) and pink (Danish cohort). For the NEUS cohort, only MHC-I alleles differentially expressed between patients with CALR^MUT MPN compared to both patients with JAK2^V617F MPN and U.S. Caucasian population were considered for further analysis. (D) Heatmap of predicted binding of each CALR^MUT-derived peptide to each MHC-I allele from (B) (left). MHC-I alleles that are underrepresented or overrepresented in patients with CALR^MUT MPN in both cohorts are noted with white or black circles, respectively. Actual MHC-I allele frequencies in CALR^MUT and JAK2^V617F MPN patient populations are also noted (right). (E) Cohort breakdown of CALR^MUT MPN MHC-I allele frequencies of individual institution consisting of the NEUS cohort for the six less frequent MHC-I alleles.