Although mature immunoregulatory DCs have been identified in various cancers, the presence of this subgroup in osteosarcoma has not yet been confirmed.16,19 The mregDCs (CCR7+LAMP3+CD83+) in the current study can be referred to as CCR7+ DCs that were found by Zhou et al.11 As they mainly focused on the heterogeneity of cancer cells and T cells, the role and function of this DC subset were not fully annotated. Here, LAMP3 is linked to osteosarcoma.