PD-L1 and PDL-2 have different expression patterns; PD-L1 is expressed by several cell types, including Antigen Presenting Cells (APCs) such as macrophages and DCs, MDSCs, and tumor cells (32), whereas PD-L2 is mostly expressed by APCs and lymphocytes (33). The gene discussed is PDCD1LG2; the disease is neoplasm.