CD300ld is a protein specifically expressed on a subset of MDSCs, particularly the polymorphonuclear (PMN-MDSCs), which are a type of immune cell that plays a role in suppressing the immune response within a tumor microenvironment, making it a potential target for cancer immunotherapy; essentially, high CD300ld expression on MDSCs is associated with tumor progression and immune suppression [39]. This evidence concerns the gene CD300LD and cancer.