HLA-H and chronic lung allograft dysfunction: In cases where the immune system is challenged, the absence of HLA-H might lessen tolerogenicity; in Lung Transplant patients (LTx), the HLA-G*01:04 allele, in Linkage Disequilibrium (LD) with HLA-H*deletion, was associated with impaired long-term survival, increased Chronic Lung Allograft Dysfunction (CLAD) occurrence, and the production of de novo Donor Specific Antigen (DSA) (22).