CALR and cancer: Taken together, these data support the hypothesis of cancer immunoediting [86,91] in MPN: healthy donors display T-cell memory to mutant CALR epitopes (elimination) [87], healthy donors with CALR-mutant cells in the peripheral blood show strong T-cell responses to CALR mutations (editing) [90], and patients with overt CALR-mutant MPN show weaker and less frequent CALR-mutant-specific immune responses compared to healthy donors (escape) [84] (Figure 2).