Interestingly, MSCs from patients with mild COVID-19 transcribed high levels of CD86, HLD-DRA, HLA-DRB1, and HLA-DRB5, suggesting that these cells may play a role in the priming of T lymphocytes and act directly and indirectly in the orchestration of the immune response facing the disease. Here, HLA-DRB5 is linked to COVID-19.