MHC genes HLA-A, HLA-B and HLA-C are especially susceptible to alteration, with even human leukocyte antigen loss of heterozygosity (HLA-LOH) impairing CTL-mediated immunosurveillance in the TracerX cohort.111 We recently identified HLA-LOH in 23% of patients with MPM undergoing surgery, all of which were late evolutionary events.26 Moreover, they also displayed a more diverse predicted neoantigen repertoire than HLA-intact tumors, indicating higher susceptibility to tumor-specific CTLs. The gene discussed is HLA-C; the disease is neoplasm.